How to get Ants to carry a sign - Smarter Every Day 92

Hey, it's me, Destin. Welcome back to Smarter Every Day!

So, you're probably wondering, if you've been watching the Amazon series, how it took an 8-pin, a little scrap of paper, and a camera into the middle of the jungle, and walked out with footage of ants carrying a little sign that says "Smarter Every Day." It's actually pretty simple and gross: you pee on the paper. I know, sounds a little weird, but you got to realize that leaf cutter ants forage for sodium.

But before I show you how exactly we did this and you get to see us make the video, I want to show you a leaf cutter ant colony during the daytime, and then we'll go back and check out the same colony at night. We get Smarter Every Day!

This whole area is a colony. Is that what you call it?

Yeah, these colonies are known to just be giant. They're foraging ants, so they take in those leaves; they grow fungus on it. So, that's a tenth of that fungus very, very regularly. The smaller ones, they really ride on the leaf, and they clean the leaf. They also protect the carrying ant from any decapitating flies that are in the area.

Really? Mmhmm. They clean the leaf on the weighted colony.

Yeah, so one guy, like a bigger ant, will be carrying it, and the little cleaner ant will be on top. They're protecting it and cleaning it from any fungus or any crazy stuff that may be on the leaf.

Awesome! Is there red or millions of ants inside this colony?

So, this is one of several entrances—probably one of their main highways that they used to go and collect leaves. I'm also told they have one of the most complex social structures.

Yeah, that's true. Yeah, I mean down to the finest of details. Even like the ants that go out and cut, once they get old, maybe like three months old, and they can't cut as well, then they become carrying ants. So, they kind of retire as a leaf cutter and then they become a leaf carrier.

These are leaf cutter ant trails. They look like people trails, but they're not. One way you can tell, you get really close, you see next to them, you see all the little cut leaves. So, you can see some of them are starting to come out a little bit. So, I bet you if we came back in a few hours, they'd come out and go for the trees.

So, what we're going to do is we're going to cut out little pieces of paper, and we're going to put some salty liquid onto a piece of paper. We're thinking that it will entice them, but I'm going to find out.

Put your headlamp on the leaf. There you go. There you go!

All right, so what do you want to do first?

I've got the "worst smarter every day" one, and I got it wet on the backside, so it doesn't quite...

All right, it doesn't bleed, right? You know, I know mostly the area, so I put it right here.

Yeah, you want pliers? We want to put...

Need a bigger... can we make it bigger?

No, focus was perfect. So that's it! That's how you get leaf cutter ants to carry your sign. Special thanks to Mr. Torres here, of course, entomologist—he's the guy that came up with the idea.

Work well?

All right, that's it. Get Smarter Every Day!

You're not playing nice anymore—going for my face! Imagine that!

Even if I would have thought so, this one's too big. So, of course, leaf cutter ants are cutting, which is still pretty cool sounding.

Yeah, it's about 20 yards away.