Why are ants stealing my toenail clippings?

Chris Smith put this to zoologist and naked scientist Georgia Mills...

Georgia - Well firstly, may I suggest investing in a bin if you want to avoid this in future. I actually had a look on.

Chris - Sounds like he doesn't needs one. It seems like he has a sort of natural...

Georgia - . cleaning ants, yeah. Well, actually, I looked online and there's quite a few people have noticed this. People from all around the world are saying what is going on here, why do ants really like toe nails - it's a bit disgusting really?

So nails, they're made of a protein called keratin. It's the same thing your hair is made of and it's a protein. So there is nutrients in proteins, but the thing about keratin is it's notoriously difficult to digest. There's only a few species of insects that we know can digest keratin and ants, as far as I can tell, aren't one of them.

So what are they doing with it? It could be that these ants are making a terrible mistake because, if you think about your fingers, you're touching food a lot, there's dead skin cells under them, there's bacteria. It could be that there's a smell that they're very attracted to. So they think oh, there's a nice bit of food, taking it back, and then they're like oh no, we can't eat this, what have we done! We've wasted so much time!

There was one theory that I read that was quite interesting. So something we know that can digest keratin is fungus and a lot of ants are known to have these relationships with fungus where they kind of grow it as farmers and then they eat the fungus. So it could be they're putting the nails on the fungus, the fungus is getting energy from it and then the ants are benefitting from that. But, these funguses only exist in the Americas, and I think people have been reporting this from all over the world, so it must be something else going on. And I think some people have reported that ants have been seen harvesting keratin from dead bodies as well. So maybe there's a PhD in this, maybe they are digesting the keratin and there is some process we don't know about yet.

Chris - When I was wondering around in Zambia in the Luangwa forest, there were lots of remains of animals dotted about, horns and things and they all did have holes in them. And I asked the guide what had made these holes because the horns of animals are keratin aren't they and he said well, actually, certain moths will come in and lay eggs on the horns because the moths, in the same way as they eat your clothing in your cupboard, that's why you get holes from clothing moths - they do have the ability to break down and digest these horns. That wasn't ants, it clearly wasn't ants.

Peter.

Peter - Yes, keratin is also in hair isn't it - is that right?

Georgia - Yes. Which is why it's a very bad idea for you to eat balls of your own hair.

Peter - But are the ants interested in hair?

Georgia - I did actually search that and apparently not. But the keratin in your fingernails and the keratin in your hair are different structures, so maybe that's got something to do with it.