Are ants taking over the world?

I’ve been meaning to ask this question here since yesterday, so it’s funny that today’s topic would have to do with ants. My question is this: I was told by more than one person over the course of my life that ants make up one-quarter of the Earth’s weight. How true is this? If it is, just how many ants is that? Where on Earth was that much weight before there were ants?

  • Adam F.

Welcome to the boards FoamFighter.

I would seriously doubt that ants make up anything like that amount of weight.

But I’m not sure so to quote Seymore Skinner

“Prove me wrong, kids. Prove me wrong!”

Welcome to the SDMB!

Ants definitely do not make up a quarter of the earth’s mass (better use mass than weight: weight is the force that earth exerts on a certain amount of mass, but what force does earth exert on earth?). Consider the fact that the earth is a sphere. If the mass were evenly distributed, you would have to dig from the surface towards the center all around the globe as far as 10% of the earth’s radius (or about 636 km) in order to collect 25% of its mass. Given the fact that earth’s matter is much more dense at its center that within the outer 10% of the radius, you would have to dig even farther.
Anyway, digging 10% of the radius would catch all the ants, but they would still only make for a small part of the dug material. This shows that their combined mass is far from 25% of the earth’s mass.

Probably somebody stated that ants (or insects in general) make up 25% of the earth’s organic matter, which would be something completely different. However, I can neither verify nor falsify this hypothesis.

Achilles and Martin, thank you so much for responding and making a guy feel welcome.

Achilles: It seemed to me to be an implausible statement, too, but I just had to get the straight dope.

Martin: Your answer was great. Next time someone comes to me with this statement, I’ll have a means of argument.

  • Adam F.

I live on the desert and used to have a dog that I took out for walks every weekend. I’m not sure about the weight part, but around here by far the most common and certainly the most numerous form of life is ants. The most visible form that is. I suppose baceria are more numerous.

Oh, and…


I suppose this now begs the question: Why don’t ants have population controls like every other species? Even bacteria have population controls. Hmmm.

  • Adam F.

There are limiting factors on the population of ants; reproductive rate, availability of resources, predators, diseases, environmental conditions - just the same as any other organism.

I guess what I meant was why are ants so much more prolific than other species?

  • Adam F.

Possibly because that far down in the food chain, you can adopt a one-size-fits-all approach. You need a specific animal to eat antelope and a different specific animal to eat rabbits. However, ants will eat anything. Also, every step up the food change decreases your availible biomass by an order of magnitude. Thus, ants have more available food that most other animals.

I once read that ants and termites make up 10% of the earths biomass. I’ll see if I can support that number.

Here it is
It seems reasonable by modern estimates that ants make up about 10% of the earths biomass.
I googled on ants and termites 10% earth biomass

Maybe I’m crazy but I doubt organic matter even makes up a quarter of the earth’s mass, let alone the ants.

It’s funny, I thought by the topic title the subject would be about arthropods taking over the world. I remember my biology teacher telling me that if humans had not invented pesticides then the age of arthropods (insects, spiders, crayfish, etc… for those who don’t know) as the dominant species on earth would have begun about this time.

That’s a bizarre statement; we’ve had insecticides for less than a century; what was stopping them in the millions of years before that?

(Unless he’s talking about their potential to exploit the resources which humans are creating through farming, food storage etc, in which case he kind of has a point, but still a pretty odd one, since our modern methods of farming and storage could not have come about without the advent of pesticides and preservative methods)

Ants. Bugs. Insects in general.


I say we take off, and nuke 'em from orbit.

It’s the only way to be sure.

what the ants are saying

Why don’t you ask them?

This is really selling short the diversity found in the ant and termite groups. From teeny tiny red ones to inch-long black ones and fire ants and carpenter ants and leaf-cutting fungus farming ants and killer army ants and ants that enslave other ant species and probably bizarre forms of ants in the jungle that nobody has every heard of, ants are far more diverse than the difference between antelope-eaters and rabbit- eaters. I would say ants are far more diverse than mammals, except I don’t know of any wholly aquatic ants, so I’ll leave the question open.