I recently played a flash game(Tasty Planet, if you're wondering), where you play play a glob of grey goo that eats planets wholesale. This got me thinking; Why don't the Tyranids do the same? Why do they bother with silly planetary invasions if their motivation is hunger?

Well it would be boring as an army wouldn't it but on a more serious note the Tyranids effectively do devour planets, just with multiple organisms rather than just one big one.

Feasibly a giant goo ball could be killed but matching the various Hive Fleets is much more difficult and hence the species as a whole is much more likely to survive and continue and so far they seem to have done very well so I don't see any reason for the Tyranids to be anything other than the swarm that they are.

I would guess because if they don't crush all occupying forces then the massive feeder tubes that move biomass to the hive ships could be easily destroyed causing a significant loss of resources.

Rock and lava cant be easy to digest

They want biomass not minerals. Thats a reason why they avoid the necrons. Most Tomb worlds are already devoid of life not to mention necrons phase out there damaged units hence even what little they can use out of minerals and such would be way to much of a waste.

They do. All that's left is the most useless rock. There's no point in expending energy carry around 1,000,000 tonnes of granite you're not even going to use anyway.

Well.

Plants digest rock and lava.

All living things are made of inorganic minerals, so there isn't a fundamental problem there.

If Tyranids wanted to avoid eating the rocks, they could drop some spores on a planet which would analyse the bioshere and produce a viral plague that would simply dissolve all life into goo, then suck it up.

It would be an even better way of avoiding all the flamethrower nastiness than eating the whole planet.

But really, why bother eating planets at all. There are gigatons of organic chemicals and water and so on floating around in space.

The IoM isn't interested in it, so the Tyranids could get it for free.

Also an organism of that size would be, well, huge. The bio-engineering of the Hive Mind is good, but is it good enough to produce such a colossal beasty? Also don't the Tyranids get a lot of their genetic make up/design from what they have previously consumed? So in theory that would mean that they would have to have eaten huge, planet consuming creatures in other galaxies (assuming they haven't eaten one in this galaxy, but maybe a void whale would be of the sufficient size/complexity). The complexity of the digestive system of such a planet eating nid, I assume, would be astronomical, sorting out and putting to use all the different minerals and biological material efficiently in one go.

Because it's "not in the script" would be my answer, but I'd justify it by saying that organic material has all that inorganic material can offer plus the added bonus of genetic base material which is useful to them. They are organic material and consuming such is simply natural.

On the other hand, one might say well, why not simply stay on a planet till everything is gone? A hive fleet might well take a VERY long time to reduce a planet to nothing. Taking every useful thing available. After all, organic material is just a thin layer of "pond scum" on a rock, isn't it?

Then again, maybe there IS something "motivating" the hive fleets other than pure hunger and other such simple Darwinian concepts.

Because Eldrad told them not to.

You're underestimating the sheer mass of a planet, as well as the amount of energy that would be expended to break it down. It doesn't even make sci fi science sense.

Stages of Planetary Consumption:

Generally, contact with the Tyranids occurs when a Hive Fleet invades a star system for the purpose of harvesting its inhabited worlds' biomass. A Hive Fleet contains an enormous number of Tyranids, and they are brought to bear against resistance in the most efficient manner possible.

Below is a general outline of a typical Tyranid planetary assault (in particular, this data is collected from the Tyranid invasion of Dalki-Prime):

■Day 01: Mycetic spores are dropped, mostly containing Lictors and Genestealers. As soon as they hit the ground, the reproduction of Tyranid creatures likely begins immediately.

■Day 09: By now, the Tyranid infestation will have expanded to around 250 km around the drop point, and will likely present a significant threat to planetary defense force troopers and the resident Imperial Guard.

■Day 13: Tyranids have expanded to 700 km from the drop point; some may begin infesting local water sources.

■Day 37: Tyranids completely control the area within 2,000 km radius of the drop point and basolithic infestation has begun to reach a 5,000 km radius from the drop point of the first mycetic spores.

■Day 48: Tyranid population growth becomes exponential, with population doubling approximately every 3 days.

■Day 50: The main Hive Fleet arrives, with the number of Tyranid craft in the swarm generally numbering around 1.5 billion. All psychic contact with the planet through the Warp is cut off by the Warp shadow of the Hive Mind. Any attempts to escape are quickly stopped by the Hive Fleet. Any remaining surface life is eliminated by Gaunts.

■Day 51: Primary consumption of planetary biomass begins (any sentient resistance has generally been eliminated by now). Brood ships land, releasing Ripper swarms, which consume all organic material (even the other Tyranids) and deposit it at the reclamation pools. Capillary towers (and the Brood ships) send the material into orbit for use by the Hive Fleet.

■Day 80: Ripper swarms board the Brood ships and return to the Hive Fleet. The hive ships descend into the upper atmosphere and begin collecting it. Reduction in atmospheric pressure causes oceans to boil away, which are also collected so that their free water can beused by the fleet. The loss of ocean mass causes plate tectonic shifts, dramatically increasing volcanic activity across the victimized world. Upon completion, the Hive Fleet reenters the Warp, in search of fresh prey.

■Day 100: The Imperial Navy arrives in response to the planet's original Astropathic distress call, only to find a destroyed, lifeless, uninhabitable planet.

Kilkrazy wrote:Well.

Plants digest rock and lava.

All living things are made of inorganic minerals, so there isn't a fundamental problem there.

If Tyranids wanted to avoid eating the rocks, they could drop some spores on a planet which would analyse the bioshere and produce a viral plague that would simply dissolve all life into goo, then suck it up.

It would be an even better way of avoiding all the flamethrower nastiness than eating the whole planet.

But really, why bother eating planets at all. There are gigatons of organic chemicals and water and so on floating around in space.

The IoM isn't interested in it, so the Tyranids could get it for free.

I think people underestimate how much they take. They take the air, the dirt even the diamonds. The a point of diminishing returns to hualing around a bunch of carbon.

There is a lot of carbon in organic chemicals.

If the Tyranids scooped things up from space, they could drop or spit out the carbon they didn't want.

Kilkrazy wrote:There is a lot of carbon in organic chemicals.

If the Tyranids scooped things up from space, they could drop or spit out the carbon they didn't want.

The main thing 'nids want more than anything by far is DNA. Yes, I know there's space whales flying around but the best place to go for that is still planets.

Of course the Tyranids may well have some kind of planet eating beasty, it just hasn't arrived yet and for all we know the Tyranid organisms so far revealed are the most insignificant of the Tyranid organisms. However, in the face of such a massive creature, the lesser Tyranid creatures range ahead so that they can get a feed, devouring all the biomass before the big boy turns up and eats literally everything.

Because even after all that fluff and discussion about it, it's still just a tabletop wargame.

Tyranids do kind of need to be an army to can actually play on said tabletop.

KamikazeCanuck wrote:

Kilkrazy wrote:There is a lot of carbon in organic chemicals.

If the Tyranids scooped things up from space, they could drop or spit out the carbon they didn't want.

The main thing 'nids want more than anything by far is DNA. Yes, I know there's space whales flying around but the best place to go for that is still planets.

DNA is just a chain of chemicals. Every body makes its own DNA all the time. Tyranids are masters at manipulating DNA. They can make their own DNA much quicker and better than stealing it form other people.

The purpose for going to planets is to fight people to get better at fighting people on planets in order to go to planets to fight people to get DNA and resources, but these are more easily available in space without fighting.

From what I've read the Tyrannids absorb DNA and then replicate it. Using a form of hyper-eugenics instead of creating it from scratch. Which is why a certain space marine chapter is guarding a race of creatures to prevent them (the tyrannids)from harvesting that races specific "potential".

Kind of supports the Darwinian theory of development compounded by the seeming complexity of a vast organism. Although there may be some "guiding force" or supreme intelligence which assists the species as well.

Scientists have created a synthetic genome in the lab in our own time, so how hard it would be for a species such as the Tyrannids is open for discussion. Though I think it's possible that both ideas may be true, unless there is some specific drive which causes Tyrannids to create DNA, which I don't think is supported in the text (or is it?!), that the Darwinian absorb and modify is the easiest explanation for why they don't devour the whole planet.

Then again... http://en.wikipedia.org/wiki/Geophagy

Creating synthetic DNA, and coding new DNA, are two entirely different things. The Synthetic DNA that got created has only a minor variation from the original organism (a watermark of sorts).

Cobourn wrote:Stages of Planetary Consumption:

Generally, contact with the Tyranids occurs when a Hive Fleet invades a star system for the purpose of harvesting its inhabited worlds' biomass. A Hive Fleet contains an enormous number of Tyranids, and they are brought to bear against resistance in the most efficient manner possible.

Below is a general outline of a typical Tyranid planetary assault (in particular, this data is collected from the Tyranid invasion of Dalki-Prime):

■Day 01: Mycetic spores are dropped, mostly containing Lictors and Genestealers. As soon as they hit the ground, the reproduction of Tyranid creatures likely begins immediately.

■Day 09: By now, the Tyranid infestation will have expanded to around 250 km around the drop point, and will likely present a significant threat to planetary defense force troopers and the resident Imperial Guard.

■Day 13: Tyranids have expanded to 700 km from the drop point; some may begin infesting local water sources.

■Day 37: Tyranids completely control the area within 2,000 km radius of the drop point and basolithic infestation has begun to reach a 5,000 km radius from the drop point of the first mycetic spores.

■Day 48: Tyranid population growth becomes exponential, with population doubling approximately every 3 days.

■Day 50: The main Hive Fleet arrives, with the number of Tyranid craft in the swarm generally numbering around 1.5 billion. All psychic contact with the planet through the Warp is cut off by the Warp shadow of the Hive Mind. Any attempts to escape are quickly stopped by the Hive Fleet. Any remaining surface life is eliminated by Gaunts.

■Day 51: Primary consumption of planetary biomass begins (any sentient resistance has generally been eliminated by now). Brood ships land, releasing Ripper swarms, which consume all organic material (even the other Tyranids) and deposit it at the reclamation pools. Capillary towers (and the Brood ships) send the material into orbit for use by the Hive Fleet.

■Day 80: Ripper swarms board the Brood ships and return to the Hive Fleet. The hive ships descend into the upper atmosphere and begin collecting it. Reduction in atmospheric pressure causes oceans to boil away, which are also collected so that their free water can beused by the fleet. The loss of ocean mass causes plate tectonic shifts, dramatically increasing volcanic activity across the victimized world. Upon completion, the Hive Fleet reenters the Warp, in search of fresh prey.

■Day 100: The Imperial Navy arrives in response to the planet's original Astropathic distress call, only to find a destroyed, lifeless, uninhabitable planet.

Some of this is no longer canon (for example the Tyranids no longer use the warp to travel).

I think that the Tyranids don't eat the whole planet because the gases that Mycetic Spores release (they aren't all used to transport beasties) as well as those released by the tyranid bio spires aren't capable of breaking down billions upon billions of tons of rock into the bio mass gruel that is consumed by the Tyranids.

And while DNA is important to the Tyranids as it allows them to adapt keep in mind that they are all living creatures in one way or another and so much of the harvested biomass goes to providing the energy for all those life forms either by creating them or allowing them to live.

Minerals (magma and lava are just minerals in liquid form) hold very little nutrients and so the energy spent breaking them down woulden't be worth the energy consumed from them. That's why very few if any creatures on Earth eat rocks for purpose of protein, now yes some minerals are important and are ingested through the food we eat but that food isn't rock. It's the same thing with the Tyranids, they're just a mass of living creatures seeking to further their existance on a planetary scale.

Yeah, I was trying to make that point, but stopped short. Synthetic DNA being as far as we've come with 21st century tech. How far can the Tyrannids go in the 41st milenium?!

Creating DNA seems too technologically specific. It sort of implies building constructs without the benefit of specific experience. Instead of fast eugenics which is how I see the Tyrannids. I hope I'm not missing out on a bunch of fluff which says otherwise.

In that case ignore everything.

Because I imagine that the rock isn't to tasty...

Because we are playing Plothammer and not Sensiblehammer

@Killrazy
Tyranid are unique in that they are fully cognizant and fully in control of their dna. Norn Queens move genones around like lego pieces. They cannot it would appear evolve new genomes on their own or are subject to the slight mutations normal life has every generation. In the end, they are literally gene stealers.

Exactly.

So they have no need to attack planets in order to get genes that are good for attacking planets in order to get genes that are good for attacking planets.

Kilkrazy wrote:Exactly.

So they have no need to attack planets in order to get genes that are good for attacking planets in order to get genes that are good for attacking planets.

That's equivilent to the crazy guy on the radio who says we should stop all research because we've already invented everything we need.

No it's not.

Tyranids can make their own genes.

They have no reason at all to pinch the genes of a 21,798th human planet.

Planets are too big. The world's deepest drill is 7 miles deep, two feet wide and has taken many years to reach said depth. 7 miles is like a grain of sand gouged into the skin of a watermelon. To process an entire planet is near impossible.

Also, if they have no planet, food can't regrow on the planet.

I always thought the Tyranid hunt for the macguffin of 'biomass' was inherently a little bit flawed- rather than expend the resources to create huge monstrosities, if the nids dropped something more akin to a virus (using their genome manipulating skills to make it work along the best infection vectors) imagine an airborne ebola virus that had a 100% fatality rate dropped on a major population center- you could have an entire planet dead and being converted into tyranid chow within a month.

Kilkrazy wrote:No it's not.

Tyranids can make their own genes.

They have no reason at all to pinch the genes of a 21,798th human planet.

To get material. It's logical to think they can digest biomass easier than processing raw materials like a machine as per all known life. You can't make it not make sense Kilkrazy no matter how much you try!

Mewiththeface wrote:Also, if they have no planet, food can't regrow on the planet.

Food can't re-grow on the planet as it is? once the Tyranids are done with it it's a lifeless rock with no atmosphere or water. Without those things life can't come back to the planet.

They'll replenish with time actually (volcanic activity releases a lot of both), though I don't know that nids plan a billion or two years in advance.

KK, it doesn't matter how much extra stuff there is in space. They'll still attack the planets. Tyranid are literally insatiable and they will not stop eating until:

A) They are destroyed.
B) There is nothing in the universe left to eat.

Slick wrote:I always thought the Tyranid hunt for the macguffin of 'biomass' was inherently a little bit flawed- rather than expend the resources to create huge monstrosities, if the nids dropped something more akin to a virus (using their genome manipulating skills to make it work along the best infection vectors) imagine an airborne ebola virus that had a 100% fatality rate dropped on a major population center- you could have an entire planet dead and being converted into tyranid chow within a month.

They already do this - not that fatal though. The same spores that promote explosive growth of the flora on the planet also kills fauna. Basically the air becomes toxic to anything not a plant. The reason this doesn't do anything in game terms - and why they don't do anything even more lethal on a planet wide scale, is again, the army needs to be playable on the tabletop. It's fluff for a tabletop wargame.

However, also related to this, the Tyranids have something more fatal than the spores released at the start of an invasion. Venomthrope spores. These literally liquefy your organs after a minute or so of exposure. Why don't they use these on a planet wide scale to remove all defenses? Tabletop wargame.

KamikazeCanuck wrote:They do. All that's left is the most useless rock.

And not so useless metal.

Metals and minerals are consumed, broken down into their base chemicals. They leave rock behind, nothing else.

Metals are essential to life forms. We do happen to have iron in our own blood, afterall.

edit - bad wording

-Loki- wrote:Metals and minerals are consumed, broken down into their base chemicals. They leave rock behind, nothing else.

Metals are essential to life forms. We do happen to have iron in our own blood, afterall.

edit - bad wording

What he said. They take the all the Iron, Gold, platinum and the other good stuff too.


Automatically Appended Next Post:
Well I shouldn't say all the Iron and nickel. They wouldn't take the molten core obviously.

Requia wrote:They'll replenish with time actually (volcanic activity releases a lot of both), though I don't know that nids plan a billion or two years in advance.

Volcanic activity dosen't release water unless it opens up underground rivers or lakes which then evaporate do to the heat, the water that woulden't evaporate has either been consumed by the Nids or boiled away due to the lack of an atmosphere that previously protected it from the sun.

Volcanic activity may release gas but not enough to re-create an entire atmosphere and even if it did have time to build up enough to be stable there woulden't be any water at that point which is essential to life. Without an atmosphere and direct contact with space the planet would cool, the core would die and stop spinning, when the core stops spinning the electromagentic field surround the planet dies causing the surface to be bombarded with radiation.

The planet would litterally be dead and would never have life again. Why do you think the Moon is lifeless and has no atmosphere or enternal heat. When it says that it's a barren lifeless rock it means it's a barren lifeless rock, planets have to walk a very tight balancing act to be able to support life and the only reason so many of them do in 40k is because the Old Ones engineered them to. So no the planets devoured by the Tyranids will not re-grow life.


Automatically Appended Next Post:

-Loki- wrote:Metals and minerals are consumed, broken down into their base chemicals. They leave rock behind, nothing else.

Metals are essential to life forms. We do happen to have iron in our own blood, afterall.

edit - bad wording

Trace amounts of Iron. We get the minerals in our bodies as transfer from what we eat either directly from plants or from the animals that ate the plant. We don't eat metal or rock and so the Tyranids woulden't need to eat it to get essential minerals because they would get it as transfer from the bio matter they harvest which is easier to break down then billions of tons of rock and metal.

The Tyranids don't consume entire planets because the energy gained would not be greater then the energy spent.

-Loki- wrote:Metals and minerals are consumed, broken down into their base chemicals

So you're saying that they devour a planet's metallic core? Because I find that idea to be laughably ludicrous.

I always thought that the Tyranid's may just leave what is left directly above the mantle. It is probably very hard to gather and digest rock that is thousands of degrees.

Why don't they just devour planets whole?

Well... they do. Surrounding it and falling on the planet the way we know is just the way they do it.

Tyranids will consume the first few layers of rock in order to consume metals. Metal will obviously be left on the inside of the planet, but it takes too much energy to consume the inside of a planet.

Can Tyranids kill a planet completely? Shutting down the core, stopping its magnetic field?

It's not unlikey that the 'Nids could process almost all useful materials from a Planet. They could quite easily strip a planet clean.

They're already here!

As for bacteria living in lava? You never know what goes on in the core, bacteria can be found around thermal vent today so...

Arsenic bacteria has recently shattered perceptions about life and survivable conditions in which it can develop.


The reason they don't devour planets whole is simply because they would end up being space basking sharks of colossal proportions. You couldn't field that now could you. 'Nids could work as a virus type effort, a la 'The Thing' or 'The Flood'. Virus digests host, while the host proliferates the contagion.

Once again, I find it extremely unlikely that they devour a planet's core. The amount of mass in a planet's core, most of which is usually metal, is enough to cover the surface millions of times over. We're talking about a 5000 kilometer sphere of iron and nickel for an earth-sized planet. Radius, not diameter.

With the mass gained from eating a single planet's core, they'd have so much more iron than biomass that tyranids would have to be MADE of iron in order to actually make use of it all-- there's more iron in a SINGLE planet's core than is likely used by the entire Imperial Navy. I don't think you guys comprehend just how tiny the crust of a planet is.

Medium of Death wrote:Can Tyranids kill a planet completely? Shutting down the core, stopping its magnetic field?

By cause and effect yes they can. I was hoping I didn't have to go through this but here it is.

The Tyranids remove all biomatter and the majority of water from a earth like planet, the flora which once converted carbon dioxide into oxygen are now gone (also remember that oceans produce oxygen to).

The build up of Carbon Dioxide eats through the ozone letting increased amounts of radiation break through the atmosphere. This combined with the heat already trapped by the Carbon Dioxide would increase the temperature of atmospheric gases, as their molecules began moving faster the gases escape velocity would increase which would allow them to escape the planets gravitational pull causing the atmosphere (composed of various gases at various temperatures and densities) to slowly bleed off into space.

Then the reverse happens. As gases bleed off there is less and less atmosphere, since there is less atmosphere the temperature of the planet starts to drop because it is gases that trap healthy amounts of radiation (and heat) which keep a planets surface warm.

As the temperature of a planet drops eventually the molten material at it's center will start to harden and prevent the core from spinning either entirely or partially. If the planets core is no longer spinning or spinning at a slower rate then the planets electromagnetic feild will be gone, what little water that may have been left on the planet would be frozen pockets trapped deep inside the planets mantel.

By this point those gases that where dense enough to stick to the planet based off gravity alone are gone because if a core stops spinning the planet also loses momentum in it's rotation lessening some of the planets gravitational pull (the same principle as G-forces pulling you down into your seat when on a roller coaster) so it's no longer strong enough to hold the gases.

So now the planet has become a cold, barren and iradiated rock with no atmosphere, very little water and no way of supporting life. It is a dead planet, and while this woulden't happen instantly and the time period that this happened in would depend on the size and density of the planet it would happen alot quicker then the time it took for a planet to "re-grow" life. So yes Tyranids can kill a planet if they're invasion is successfull.

Here is a quote directly from the codex which describes a planet after a Tyranid invasion

Kryptman found a blasted and sterile planet, now unrecognisable as the teeming ocean world it had once been. The planet had been sucked dry, every scrap of vegetation and every drop of water consumed

No one said they eat the core! In fact I specifically said they don't.

Who was that in response to?

Are you responding to me? I was responding to melissia. Got ninja'd.

To clear things up, I asked why the Nids eat a planet in one single gulp, sort of like a giant meatball made of Iron and rock. Here's my theory: It's been mentioned the current nids could be just a scouting force for the bigger bugs. One of these types could be a the Galactus version. I know that planets have more rock than the crust in exponential numbers, but the Tyranids are an extragalactic race. They should have more than enough resources to make something of that magnitude.

We know what you're asking and it's been answered, the Tyranids don't just swallow whole planets because they have no need to. The amount of energy spent digesting so much mass would be greater then the energy gained from eating it.

And the problem with your theory is if there was just a huge bug that swallowed entire planets why would they need a scouting force, something that big woulden't send out scouting forces to devour the biomass of every planet only to come along and eat a barren hunk of rock. Something that big would just drift through space untill it found a planet and it would consume it since there would be nothing that could stop it.

Also something that big is going to be generating gravity close to a planet itself. Something biological just can't be that big.

KamikazeCanuck wrote:

Kilkrazy wrote:No it's not.

Tyranids can make their own genes.

They have no reason at all to pinch the genes of a 21,798th human planet.

To get material. It's logical to think they can digest biomass easier than processing raw materials like a machine as per all known life. You can't make it not make sense Kilkrazy no matter how much you try!

Yes, I can.

Plants and bacteria process raw materials just fine. That is how an ecosystem works.

Tigers need to eat deer, and deer need to eat grass. Tyranids don't need to be tigers or deer, they are a complete ecosystem of interdependent organisms which control their own evolution and have access to collossal resources in space without ever having to touch a planet.

The slight advantage of sucking up decayed biomass from a planet's surface, rather than simply harvesting resources in space, is more than offset by the effort required to do the job.

Tyranids don't make any kind of sense, except as an excuse to have an "Aliens" style army in the game.

KamikazeCanuck wrote:No one said they eat the core! In fact I specifically said they don't.

No, they said that the Tyranids also eat all of the valuable metals on the planet.

Which the core is made of.

Dominatrix! Surely the inner nature of the Nids is evil and feeds off negative psychic energy? The suffering of a pre devoured population and war in general are juicy etheric yum yum.

Rochronos wrote:Dominatrix!

Not sure why you brought this up since it isn't large enough to eat a planet whole

Melissia wrote:

KamikazeCanuck wrote:No one said they eat the core! In fact I specifically said they don't.

No, they said that the Tyranids also eat all of the valuable metals on the planet.

Which the core is made of.

They have to get to the core first...

Kilkrazy wrote:

KamikazeCanuck wrote:

Kilkrazy wrote:No it's not.

Tyranids can make their own genes.

They have no reason at all to pinch the genes of a 21,798th human planet.

To get material. It's logical to think they can digest biomass easier than processing raw materials like a machine as per all known life. You can't make it not make sense Kilkrazy no matter how much you try!

Yes, I can.

Plants and bacteria process raw materials just fine. That is how an ecosystem works.

Tigers need to eat deer, and deer need to eat grass. Tyranids don't need to be tigers or deer, they are a complete ecosystem of interdependent organisms which control their own evolution and have access to collossal resources in space without ever having to touch a planet.

The slight advantage of sucking up decayed biomass from a planet's surface, rather than simply harvesting resources in space, is more than offset by the effort required to do the job.

Tyranids don't make any kind of sense, except as an excuse to have an "Aliens" style army in the game.

What is this thing in space that is more fruitful than planets btw?

The little itty bits of stuff floating around. Interstellar Hydrogen, and bits of Carbon, and Iron, and all the rest of the elements. The thing is, even though there's maybe only one atom per lightyear, there's a whole freakin' ton of lightyears out there. There's probably more than a million times as much matter floating around in the void as there is tied up in planets and stars.

Ice comets, gas planets full of hydrocarbons, dust and gas clouds full of ethanol, uninhabited moons where you won't get flamethrowered for sucking up the methane oceans, endless free sunlight to power you.

A canny hive fleet could probably even get paid by the IoM for clearing cosmic debris out of the star lanes.

As I said, though, it would not get an "Aliens" style army into the game.

Kilkrazy wrote:
Yes, I can.

Not really, as you're missing the point completely.

If you're trying to argue that it is more logical and efficient to avoid the resistance on planets and just eat space-stuff, then you are right, as it is more efficient. The problem is that, while that fact is true, it's irrelevant. You seem to think that if we just give them something to keep them occupied they'll leave us alone because theres more than enough space-stuff for them to eat. But that would imply that they have a certain limit on their hunger; a point at which they are happy with their supply of food. That is not the case. The Tyranids don't care if one source of food is easier to get than another. They want to eat both, and they don't care what it takes to get it all. Because their appetite is insatiable.

Let's say you're a really obese man who loves donuts and has an insatiable appetite for them. You're sitting in a donut shop eating donuts. Across the street, there is another donut shop with donuts that are only slightly better than the one you're eating. You would have to walk through the rain to get to the other donut shop. Now it may seem more logical to just be content with the supply of donuts you have right now than to go out in the rain for donuts that are only slightly better; but not if you are insatiable. You want both places' donuts. You want ALL the donuts. You'll spread yourself incredibly thin if it means you'll get more donuts, even if the lengths you go to to get those donuts don't make sense to a normal person.

As I said, the Tyranids can't be sated. They won't be happy just eating the stuff that's floating around in space. It won't be enough to sate them. They want to eat everything in the galaxy that is edible, and will go to great lengths to do it.

Kilkrazy wrote:
Tyranids don't make any kind of sense, except as an excuse to have an "Aliens" style army in the game.

Besides the looks Xenomorphs and Tyranids have almost nothing in common, so in what way do the Tyranids mirror the Xenomorph's "style" in the galaxy? They aren't an intergalactic ant colony. They're far more complicated than that.

Kilkrazy wrote:There is a lot of carbon in organic chemicals.

If the Tyranids scooped things up from space, they could drop or spit out the carbon they didn't want.

The real meaning of the song "Lucy in the sky with Diamonds"... Tyrannid poop.

Anvildude wrote:The little itty bits of stuff floating around. Interstellar Hydrogen, and bits of Carbon, and Iron, and all the rest of the elements. The thing is, even though there's maybe only one atom per lightyear, there's a whole freakin' ton of lightyears out there. There's probably more than a million times as much matter floating around in the void as there is tied up in planets and stars.

Kilkrazy wrote:Ice comets, gas planets full of hydrocarbons, dust and gas clouds full of ethanol, uninhabited moons where you won't get flamethrowered for sucking up the methane oceans, endless free sunlight to power you.

A canny hive fleet could probably even get paid by the IoM for clearing cosmic debris out of the star lanes.

As I said, though, it would not get an "Aliens" style army into the game.

The idea that there's more material floating around in the void and ice comets rather than planets is more than dubious. Planets provide the greatest concentration of the greatest variety of elements and complex compounds.
As for uninhabited planets you're assuming 'nids aren't spoiling for a fight. A powerful 'nid fleet wants to get in a fight as long as it wins. A fight means complex life and therefore delictable complex DNA. Like I said before eating for tyranids is analogous to researching for humans. They control their DNA but they don't invent new genomes they only steal genomes.

Now it would be nice for everyone if the Tyranic superorganism tranversed the void eating stray atoms like a blue whale eats plankton but that is not the way the 'nids digest. Just like how you Kilkrazy are a Man or possibly a Mandrill (reports vary) you cannot simply go eat dirt. Soil is very rich in everything we need but that's not how we obtain nutrients. First we must go through the ecosystem process. We need to turn that dirt into corn then of course turn that corn into high-fructose-syrup to obtain the soil's nutrients (I think my science teacher said the last step is the most nutritious).

You then correctly argued that the Tyranid themselves are an ecosystem all in their own. That's right! but then you said that's why they don't need to do the above. In fact its the complete opposite. That's exactly why they do need to do it. Tyranoforming is the process by which this militant ecosystem digests and makes available everything in the atmosphere and planet's crust. The base materials still need to be turned into biomatter for digestion. Before the invasion a planet is prepped by having its plant fauna goes so ballistic that soil depletion is acheived in 2 weeks. Further scary tendril stalk thingys sprout up too. Basically the whole planet gets turned into goo then eaten. All that stuff you mentioned about bacteria breaking down this and plants breaking down that is done by the tyranic ecosystem; and its done for an entire planet in a couple weeks. Not too shabby if you ask me.


Automatically Appended Next Post:
p.s. and they get some new shiny DNA to use too.

KamikazeCanuck wrote:

Anvildude wrote:The little itty bits of stuff floating around. Interstellar Hydrogen, and bits of Carbon, and Iron, and all the rest of the elements. The thing is, even though there's maybe only one atom per lightyear, there's a whole freakin' ton of lightyears out there. There's probably more than a million times as much matter floating around in the void as there is tied up in planets and stars.

Kilkrazy wrote:Ice comets, gas planets full of hydrocarbons, dust and gas clouds full of ethanol, uninhabited moons where you won't get flamethrowered for sucking up the methane oceans, endless free sunlight to power you.

A canny hive fleet could probably even get paid by the IoM for clearing cosmic debris out of the star lanes.

As I said, though, it would not get an "Aliens" style army into the game.

The idea that there's more material floating around in the void and ice comets rather than planets is more than dubious. Planets provide the greatest concentration of the greatest variety of elements and complex compounds.
As for uninhabited planets you're assuming 'nids aren't spoiling for a fight. A powerful 'nid fleet wants to get in a fight as long as it wins. A fight means complex life and therefore delictable complex DNA. Like I said before eating for tyranids is analogous to researching for humans. They control their DNA but they don't invent new genomes they only steal genomes.

Now it would be nice for everyone if the Tyranic superorganism tranversed the void eating stray atoms like a blue whale eats plankton but that is not the way the 'nids digest. Just like how you Kilkrazy are a Man or possibly a Mandrill (reports vary) you cannot simply go eat dirt. Soil is very rich in everything we need but that's not how we obtain nutrients. First we must go through the ecosystem process. We need to turn that dirt into corn then of course turn that corn into high-fructose-syrup to obtain the soil's nutrients (I think my science teacher said the last step is the most nutritious).

You then correctly argued that the Tyranid themselves are an ecosystem all in their own. That's right! but then you said that's why they don't need to do the above. In fact its the complete opposite. That's exactly why they do need to do it. Tyranoforming is the process by which this militant ecosystem digests and makes available everything in the atmosphere and planet's crust. The base materials still need to be turned into biomatter for digestion. Before the invasion a planet is prepped by having its plant fauna goes so ballistic that soil depletion is acheived in 2 weeks. Further scary tendril stalk thingys sprout up too. Basically the whole planet gets turned into goo then eaten. All that stuff you mentioned about bacteria breaking down this and plants breaking down that is done by the tyranic ecosystem; and its done for an entire planet in a couple weeks. Not too shabby if you ask me.


Automatically Appended Next Post:
p.s. and they get some new shiny DNA to use too.

These points have been made before.

In addition, removing the oceans and the ice would cause massive upheaval in the earths crust. The crust mind you. In our own time, Greenland has "risen" quite a bit as the ice recedes. This has caused earthquakes etc...

Imagine removing the oceans at a swipe. Billions of tons of water removed quickly would cause massive fracturing.

A "neat" way of strip-mining a world.

What the tyrannids are said to would not just leave a barren moon-like world as in the fluff, but it would be a molten, heaving mess instead. Rife with volcanoes.

As far as humans eating dirt, once again...

http://en.wikipedia.org/wiki/Geophagy

Dang-it... I hate editing.

Maybe Tyranids do eat the materials floating in space. The theory that there is a massive Tyranid force looming out there would support this.

Plus eating planets would be comletely conter-productive

But Tyranids are organics and eat organics. Why would they eat precious materials at all? For their survival they only need a planet full of life, not an asteroid full of Iridium...

Darth Bob wrote:

Kilkrazy wrote:
Yes, I can.

Not really, as you're missing the point completely.

If you're trying to argue that it is more logical and efficient to avoid the resistance on planets and just eat space-stuff, then you are right, as it is more efficient. The problem is that, while that fact is true, it's irrelevant. You seem to think that if we just give them something to keep them occupied they'll leave us alone because theres more than enough space-stuff for them to eat. But that would imply that they have a certain limit on their hunger; a point at which they are happy with their supply of food. That is not the case. The Tyranids don't care if one source of food is easier to get than another. They want to eat both, and they don't care what it takes to get it all. Because their appetite is insatiable.

Tyranids aren't eating the stuff floating around in space. That refutes your argument.

If you think the Tyranids weren't inspired by Aliens, you obviously are unaware of the film and game history of the 1980s.

I only mentioned the Dominatrix to highlight the fact that no one in this thread has discussed the malicious nature of the Nids. Anyone who's seen Alien knows that they hate all other life forms. So fluff wise the armies that fight any defenders are all about pain and suffering NOT planet devouring. This is done with a mixture swarms, biological agents and space hoovers.

In Alien, the Aliens are speculated to be an artificially produced biological weapon.

I used to think that the Tyranids must be the same, however of course since they control their evolution, they would swiftly evolve away from a way of life that involves get lasered to death all the time.

We know that Tyranids don't drain the suffering of their victims -- that is Deldar and Necrons.

Besides, if they did, it would be easy to create their own sacrificial victims, since they control evolution, etc.

The stuff floating in space however is probably very spread out and hard to find. IN the grand scheme of things it is very close, but for Tyranid ships to gather even a cluster of floating water and what-not would take a LONG time.

Kilkrazy wrote:

Darth Bob wrote:

Kilkrazy wrote:
Yes, I can.

Not really, as you're missing the point completely.

If you're trying to argue that it is more logical and efficient to avoid the resistance on planets and just eat space-stuff, then you are right, as it is more efficient. The problem is that, while that fact is true, it's irrelevant. You seem to think that if we just give them something to keep them occupied they'll leave us alone because theres more than enough space-stuff for them to eat. But that would imply that they have a certain limit on their hunger; a point at which they are happy with their supply of food. That is not the case. The Tyranids don't care if one source of food is easier to get than another. They want to eat both, and they don't care what it takes to get it all. Because their appetite is insatiable.

Tyranids aren't eating the stuff floating around in space. That refutes your argument.

If you think the Tyranids weren't inspired by Aliens, you obviously are unaware of the film and game history of the 1980s.

No, I am aware of the fact that they were inspired by Aliens, but over the years they have very much become an independant entity with little to no relation (other than aesthetics) to the Xenomorph species. Arguing that the Tyranids are just in there for Alien fanboys (like me) is a bit silly, as, like I said, Tyranids are a far more complicated bug than that.

Why would you outline the details of Tyranids devouring space debris when it's far more interesting to focus on the planets. Your argument doesn't work because even if they DID go after Space debris, that wouldn't replace the planets. The reason GW doesn't specifically acknowledge Tyranids eating the stuff in space is because it's really not interesting for fluff development, nor is it that important.

Besides, they've already stated that the Tyranids won't stop until there's nothing left to eat. Which would imply they eat EVERYTHING that is edible. The reason specific mundane stuff such as them eating space debris hasn't been mentioned is either:

A) It isn't significant enough to waste ink on.
B) Slipped the authors minds.

If you try to blend science fiction with science fact then you're always going to find plotholes. The stuff is very unlikely to exist or ever exist, and hence it is "fiction". For instance, in Predator, when Dutch covered himself with mud he was able to avoid the infra-red detection of the Predator. Well, in reality, that mud isn't going to help you at all. How about the sound effects you hear during the space battles in Star Wars and most other scifi shows/movies? Also, not possible in the real world. When you get down to the nitty-gritty, and over-analyze, most of the stuff you find in 40k and other things in the scifi genre don't make much sense. Overall though, I think the idea of the Nids is a pretty solid one as far as 40k stuff goes. It's got its flaws, but I wouldn't venture to say it "makes no sense at all".

I was going to start a new thread to ask this, but this thread seems to be on my line of thinking, so I'll just ask here:

What happens to the materials that the Tyranids don't assimilate? We know that they avoid Necron Tomb Worlds if at all possible, so that says that they don't care to digest just any matter, but they want biomass. Well, let's say they're fighting a legion of Space Marines on a distant world and the tyranids finally overcome them - what happens to all the power armor, power swords, thunder hammers, storm shields? Are they left out in the dust of a barren planet? Are there worlds out there devoid of life, but rich in material treasure?

Well, first off, if the 'nids have managed to defeat them, then most of that stuff is probably not in very good condition. But yeah, I think a lot of that might be lying around, depending, of course, on whether or not they can digest it. Since they can spit acid that will go through ceramite, I'd imagine when they drag the bodies (without bothering to strip them) to the, what are they called? Feeder Pools? and dunk them, everything just dissolves.

The more I think about it the more I realize GW has been very consistent in saying the only eat biomass - just like most lifeforms. They cannot consume raw materials in space, unless it's a space-whale or something like that.

I assume Tyranids drink water.

Kilkrazy wrote:I assume Tyranids drink water.

An odd assumption to make, many animals on earth don't drink water as they get it solely from eating biomass so there is little reason for nids to do it.

Kilkrazy wrote:I assume Tyranids drink water.

I do too. I also think they're solar powered for the most part.

corpsesarefun wrote:

Kilkrazy wrote:I assume Tyranids drink water.

An odd assumption to make, many animals on earth don't drink water as they get it solely from eating biomass so there is little reason for nids to do it.

I agree, the amound of fluidds, esp. blood, in what they eat would probably be sufficient.

I would imagine a basic gaunt is only given enough food and fluids to last a couple of hours of war. Then, it either finds its own, or synapse is still around and it is willed into the biomass pools to be reabsorbed.

Mewiththeface wrote:I would imagine a basic gaunt is only given enough food and fluids to last a couple of hours of war. Then, it either finds its own, or synapse is still around and it is willed into the biomass pools to be reabsorbed.

The 5th edition codex basically describes Hormagaunts like this. Basically, they land, emerge from their pod, lay eggs, and find something to kill. Because of their hyperactive metabolism, they burn out quickly. By the time they burn out, the eggs have hatched, matured and form the second wave, laying eggs of their own. So while Hormagaunts do die droves, they at least don't take up as much biomass since they provide their own following waves of attack through laying eggs. Which in turn provides more biomass to be recovered when the ripper carpet reaches them bodies.

corpsesarefun wrote:

Kilkrazy wrote:I assume Tyranids drink water.

An odd assumption to make, many animals on earth don't drink water as they get it solely from eating biomass so there is little reason for nids to do it.

It's not at all an odd assumption.

Few animals get their water solely from consuming plants or animals, compared to millions that drink liquid water.

By few you mean the majority, right?

Mind you, most of these are small insects, but so are the majority of species of Animalia/Metazoa.

I think to be fair it comes down to the codex writing, If 'nids did just eat a whole planet, the codex would be one page, and would consist of one entry:
HQ
Tyranid Planet Eating Monstrosity - 100% of points limit
Special rules: Takes up 1 HQ and 2Troops choices
Wargear: Planet Eating Jaws - Each turn roll a d6, on a 2+ you win the game

I kind of think GW wants their moneys worth out of the rules writers.

Besides, everyone knows that things large enough to eat planets are vulnerable to robots that are more than meets the eye...

I honestly believe that Tyranids can digest whatever they want in the way of material. What dictates what they cant though is temperature really. Water is H20, stars run on Hydrogen and fuse it together and make much more dense material. If stars weren't insanely hot I believe they could eat them as well. Same goes with the core of a planet..... its really hot.

Given an unfeasible amount of time, resources, or energy, anything can be broken down into its constituent parts. The argument is more about whether or not Tyranids do such things.

Melissia wrote:Given an unfeasible amount of time, resources, or energy, anything can be broken down into its constituent parts. The argument is more about whether or not Tyranids do such things.

I think that they can do that. But their primary goal is to consume all available bio-matter and that's it. I have never heard of a Tyranids consume entire planet ( but I reckon that that will be more troublesome because planet size + gravity effect) or raw materials ( if that was the case they will also attack Necron Tomb Worlds because Necrons are largely covered in metal ). So the answer to your question is they can, but they won't - because they do not do this kind of things. ( it's like asking can a Space Marine to raise a child, they can do that but they won't - because they are built for war. ).

The feasability of the Tyranid race shouldn't really factor into it - yes, it's unfeasable for a race to slowly digest a planets biosphere and suck it up through large straws.

But so is a race of fungal man-apes that make technology work through latent psychic ability. So is an alternate dimension with four rival Gods that is used for fast interstellar travel.

Tyranids aren't any more ridiculously unfeasable than pretty much everything else in 40k.

Unsure if this has been said before, but 'Nids don't eat non-biological matter. That's why it's called BIO-mass.

SgtSixkilla wrote:Unsure if this has been said before, but 'Nids don't eat non-biological matter. That's why it's called BIO-mass.

This is 4th ed fluff from GW's website. While an edition old, new fluff doesn't dispute it. note that it mentioned that minerals are consumed. They literally eat the planet down to the bedrock.

Lord Commanders,

I bring you grave news. The threat we face may be far more vast than we ever dreamed. Technical analysis of Dalki-Prime pre Tyranid consumption survey information when cross-referenced with the data from Dalki-Mons post Tyranid consumption shows some startling information.

Dalki-Prime was an agricultural planet with a diameter of 12,500 km, slightly smaller than Terra. The Tyranid fleet was able to remove the following quantities of material from the planet within 100 days [Terran Standard].

1.55 billion cubic km water, one cubic km of sea water weighs over 1 trillion kg.
8.67 billion cubic km gases, at STP theoretically they could reduce this to 1 tenth its volume by super cooling and pressure (3 atm, and 0ºC).
72 million cubic km soil and minerals, weighing 1.4 trillion kg per cubic km.

It is nearly inconceivable how they were able to accomplish this in such a short time, much less explain where the materials were taken, as the typical hive fleets encountered historically are not capable of transporting even a fraction of this volume. Over 10 billion cubic kilometres of material was removed from the planet. This would require untold millions of ships and is far beyond the scope of the entire Adeptus Mechanicus to accomplish given a decade. Most astonishing is that this is insufficient to sate their hunger and they strike again and again, often within months. We must somehow determine if these fleets are somehow sending material back to their home systems for it seems obvious that they are not using all the materials.

Detailed analysis of devastated worlds have yielded the following data in conjunction with orbital surveillance satellite and data recordings which were recovered.

Magos Biologis Salk,
Draco Legion Biomedical Research station, New Hallefuss

-Loki- wrote:

SgtSixkilla wrote:Unsure if this has been said before, but 'Nids don't eat non-biological matter. That's why it's called BIO-mass.

This is 4th ed fluff from GW's website. While an edition old, new fluff doesn't dispute it. note that it mentioned that minerals are consumed. They literally eat the planet down to the bedrock.

Bold for emphasis. That means down TO the bedrock.

-Loki- wrote:

Lord Commanders,

I bring you grave news. The threat we face may be far more vast than we ever dreamed. Technical analysis of Dalki-Prime pre Tyranid consumption survey information when cross-referenced with the data from Dalki-Mons post Tyranid consumption shows some startling information.

Dalki-Prime was an agricultural planet with a diameter of 12,500 km, slightly smaller than Terra. The Tyranid fleet was able to remove the following quantities of material from the planet within 100 days [Terran Standard].

1.55 billion cubic km water, one cubic km of sea water weighs over 1 trillion kg.
8.67 billion cubic km gases, at STP theoretically they could reduce this to 1 tenth its volume by super cooling and pressure (3 atm, and 0ºC).
72 million cubic km soil and minerals, weighing 1.4 trillion kg per cubic km.

It is nearly inconceivable how they were able to accomplish this in such a short time, much less explain where the materials were taken, as the typical hive fleets encountered historically are not capable of transporting even a fraction of this volume. Over 10 billion cubic kilometres of material was removed from the planet. This would require untold millions of ships and is far beyond the scope of the entire Adeptus Mechanicus to accomplish given a decade. Most astonishing is that this is insufficient to sate their hunger and they strike again and again, often within months. We must somehow determine if these fleets are somehow sending material back to their home systems for it seems obvious that they are not using all the materials.

Detailed analysis of devastated worlds have yielded the following data in conjunction with orbital surveillance satellite and data recordings which were recovered.

Magos Biologis Salk,
Draco Legion Biomedical Research station, New Hallefuss

Again, bold for emphasis. Also, soil is mostly decomposed bio-mass, which is how plants can feed on it. The mineral part might just be ignorance on the part of the author, because everywhere I've seen it mentioned, it says that the 'nids leave the planets as barren husks of rock. Which means they don't eat rocks.

I notice a lot of people saying that tyranids can create their own DNA but as far as I've read in the fluff (if someone can quote me a page I'll accept I'm wrong) they don't create, they move like legos. By that logic, they'd need the lego bricks to move them in the first place...they don't create new dna, they adapt the dna they have catalogued to suit their needs. The prime example is the tyrant guard, who clearly have the same fused rib bone plate as the space marines they've killed. They adopt new genes that suit their uses, like the Borg in Star Trek, they don't just make new stuff. I.e., they're moving lego blocks, not melting them down into plastic and pouring them in a mold to make something new of plastic. Also, the reason they kill worlds is survival. To quote the Gah Lak Tus miniseries from the ultimates "Space is big, it takes a lot of energy moving that distance". They grab biofuels to revitalize their engines. As to the spore idea, so far only venomthropes and malanthropes have been witnessed producing those sorts of pathogens, and only on a small scale (compare to the size of a planet) it'd take millions of those creatures to generate the proper miasma (just like earth's atmosphere took millions of years to evolve into our breathable atmo from the volcanic smog it once was, changing the atmosphere takes a massive effort) Thus to prevent defenders from killing the thropes they need defensive forces, which they evolve like starcraft units to counter their opposing forces. Finally, they do subjugate worlds, that's what genestealer broods are for. They arrive from deep orbit (usually while the fleet's busy trucking along in space) to help subjugate the populace and make it so the planet has fewer defenses. From a logistcal standpoint, if you can accept worlds being overrun by orks in the span of months, its entirely feasable for nids to consume how they do. Sure they might have a massive sumthing or other, but even in the fluff a giant spacewale is slow, as slow as a hive ship, and even if it could consume whole planets it'd be one easily killed organism (compare battlefleet gothic to a spacewale. If the fleet can destroy a planet it can sure as hell kill one planet eater). By spreading out the swarm allows splinter actions, making it all the more difficult to eradicate, like a lizard evolving to lose its tail and survive. By being spread out, in the even of a defeat the individual organs and cells of the fleet can scatter, essentially like metasticized cancer. (probably spelled that wrong)

SgtSixkilla wrote:Again, bold for emphasis. Also, soil is mostly decomposed bio-mass, which is how plants can feed on it. The mineral part might just be ignorance on the part of the author, because everywhere I've seen it mentioned, it says that the 'nids leave the planets as barren husks of rock. Which means they don't eat rocks.

I always got the impression it was due to the destabilization of the crust. When the seas are finally removed, the planets crust would be destabilized and the surface would be an uninhabitable, volcanic mess.

Also, wether or not it was ignorance on the part of the author matters little - it was approved by GW and made public. They take the minerals.

Well. There's a single (outdated) mention of them eating minerals, but more mentions of them not eating it than I can remember. It's more likely that GW didn't have a clear picture about what "minerals" mean, than that all those other references (which are also all GW approved) are lying/wrong. They don't take the minerals.

That's the thing - GW fluff is basically 'valid until retconned'. This was never retconned. It's never been mentioned again, but that's not retconning. It's just not mentioning it. It's also the only solid bit of fluff regarding Phase 5 of the consumption of a world.

Again, wether or not they have a clear idea of what 'minerals' means doesn't stop it being written and posted on their site as official fluff.

But EVERY other official source (recorded after 4th ed.) where this is mentioned, says they leave the planet as a rocky husk. Which means they leave the rocks.

SgtSixkilla wrote:But EVERY other official source (recorded after 4th ed.) where this is mentioned, says they leave the planet as a rocky husk. Which means they leave the rocks.

Not disputing this. but it's very open to interpretation. it's possible to remove the minerals they need and still leave a rocky husk. In fact, that's what would happen. remove the minerals needed, remove the oceans, planet becomes an unstable, rocky, volcanic husk.

An outright retcon is like Ultramarines being a successor chapter to the original Ultramarines chapter that fell to Chaos. Which is how it was in Rogue Trader, but changed to them being a first founding legion in 2nd edition.

-Loki- wrote: An outright retcon is like Ultramarines being a successor chapter to the original Ultramarines chapter that fell to Chaos. Which is how it was in Rogue Trader, but changed to them being a first founding legion in 2nd edition.

I don't see the difference between the two. In your example, one source says something, a different source says something else. In mine, one source says something, a different source says something else. Aside from this, I believe we're in accord, since minerals and rocks are two distinctly different things.

Other sources say a barren husk of a planet was left.

This article just mentions what exactly was taken. Again, it's possible to remove easily reachable mineral that they need, and still leaving a barren surface.

Edit - Not to mention Hive Ships are described as having stone-like armour.

FourCartridge wrote:I recently played a flash game(Tasty Planet, if you're wondering), where you play play a glob of grey goo that eats planets wholesale. This got me thinking; Why don't the Tyranids do the same? Why do they bother with silly planetary invasions if their motivation is hunger?

Really the fluff is just bad. Done by someone who doesnt have a strong science back ground. Most of the earth's crust and mantle is made of granite which is mostly SiO2 which is biomass. They would eat everything down to the iron nickel core. They might even eat that.

It could be that the nids are incapable of making amino acids and that they need Organic material. Most animals cannot make ammino acids. Humans cant for instance, we need some intake of protein or we will die. If this was the case though they would leave more than just the rock, they would leave a lot of the excess dirt, fiber, and water around. Perhaps they strip everything off the planet and then process it in space separating the wheat from the chaff. That makes a lot more sense, but it would seem to be fairly crippling that the nids cant make their own amino acids. Perhaps they can but it just takes too much time and they want to move on faster and without wasting resources farming.

Clarifying the amino acids, animals (and humans) can still make some of those, just not all of them. Same applies to just about everything. The tyranids, having taken DNA from working ecosystem, would posess all genes necessary to produce any amino acids and other necessary molecules from scratch. This, however, is NOT efficient. Why else would we waste our time not doing so. Tyranids need energy, which is gained in large amounts only from biomass.

I think that the reason Tyranids leave the soil (and hard to reach minerals) behind is that it takes more energy to extract them and convert them to biomass than just going to the next planet and eating all biomass there. Biological matter is far easier to digest and break down to substances that provide energy. Tyranids do, after all, have to live the time that it takes for interstellar travel. I think that their ships are capable of photosynthesis or some other means of making nutrients (glucose) to live with. This would also explain why the atmosphere and oceans are taken as well. Those two, along with minerals from soil would provide raw materials for creation of nutrients during their journey to the next world. Also, although space does contain particles that can be used for creating these, they are not found in sufficient amounts to support even bacteria, let alone fleets of hive ships.