More Leaf-Cutter Ants

dear antboy –

i saw ur blog entry on leaf-cutter ant’s and that pictrue u put up waz teh suxx0rz. it was all blury cant u do better? u sed their were like millions of them u should find 1 thats in focus. also i hear u often smell bad and r shockingly hairy for some1 who cant grow a full beard.

some1 i made up

I have to say you’re remarkably critical of photography for someone who plays pretty loose and fast with the whole plural/possessive thing. Nevertheless, I can handle criticism and, yes, I admit that photo of the leaf-cutter ants in my first post was not my finest work. However, totally coincidentally, it just so happens that yesterday when I was up in a tree I brought down some of the nice young leaves and left them there overnight. When I came back today, a trail of leaf-cutter ants had found them and started taking bits of them back for food, so I decided I’d go ahead and get some better photos of leaf-cutter ants.

Here a worker of the species Atta cephalotes has just about finished cutting out a nice piece of leaf in a manageable size to carry back to her nest. The leaf-cutter ants have sharp, toothed mandibles that they use like a saw to cut out regions of leaves:

Here’s an even closer look:

Once she’s cut out a nice piece she’ll pick it up

and then carry it back to her nest, where it will be decomposed by the nest fungus, which will in turn be eaten by the ants.

So there you go.  I hope you’re satisfied by these sharper photos. For my other more well-heeled readers, I in no way intend for this response to stand as indication that abusive question-asking will get photos taken specially just for you. Asking nicely will work just fine; I just felt I should go to the trouble of answering this one particular piece of mail since I had gone to all of the trouble of inventing its author.



Dear Antboy,

My favorite animal is the tiger, but my second favorite animals are velvet worms! I was wondering, do you ever see them in Panama? Also, what do they eat? And are they really made of velvet?

Thanks for answering my questions!
Completely Fictional Reader

Dear Completely Fictional Reader –

Wow, you sure do have an impressive knowledge of obscure invertebrate phyla! While tigers are found only in Asia, I am happy to report that you can in fact find velvet worms here in Panama. While they’re pretty rare, by shocking coincidence my friend Jon just brought me one from the leaf litter in the forest yesterday!  Here’s a shot of it hanging off my desk in the lab:

Velvet worms are super-cool – they’re not really worms, and are instead in their own phylum, Onychophora. They have characteristics of both worms (Phylum Annelida) and arthropods (Phylum Arthropoda – this phylum is where you find insects and spiders and centipedes as well as crabs and other crustaceans). Onychophora is Latin for “claw-bearer”, and if you look closely at the ends of their “legs” you can see a tiny little claw there:

You may need to click on the picture and look at it full size on my Flickr page to really see the claws – they’re tiny. You may have also noticed those quotation marks around the word “legs”, and that’s because they’re not really true legs. They have no joints and are filled with fluid, relying on internal fluid pressure to maintain their shape. When velvet worms move, they move their stump feet by lengthening or contracting their body near that foot, kind of like how earthworms move.


As for what they eat, they’re predators! They eat insects, but they’re neither very fast nor can they fly, which would seem to make them somewhat unsuited for the task of eating very mobile insects, but they have a trick up their, uh, sleeve. They have slime glands in their head that can spray sticky clear slime over nearby insects, trapping them and preventing them from getting away while the velvet worm eats them slowly.

Finally, as for whether they’re made of velvet: no, no they’re not. However, they do have a velvety appearance from a distance thanks to their being covered in tiny little cone-shaped bumps called papillae, which have scales on them.

Thanks for the great questions, Person I Totally Made Up! If you want to read more about onychophorans, they have a surprisingly detailed Wikipedia page.

Gliding ants

For the past few years, I have been studying gliding in wingless insects for my Ph.D. For my new friends over at PS23 in New Jersey, that means I am doing the same degree as Mr. Evangelista – you get to go to school for lots and lots of years and learn all kinds of cool new things about the world, as well as eat lots of instant noodles.

Around about the time you all started your first day at school – and let’s just pause there for a moment while I fill my juice cup – I got really excited about a brand new discovery that had just been made. In the jungles of South America, way up in the tops of the trees, my friend Dr. Steve Yanoviak dropped a special ant named Cephalotes atratus out of a tree and noticed something very interesting. Instead of falling all the way down to the ground like a rock, it sailed like a paper airplane back to the tree trunk and landed on it! Steve thought that was weird, because the ant he threw out of the tree didn’t have any wings. So he tried a couple more, and they all glided back to the tree too! He took some videos of what this looks like, and you can see some of them on his website.

Now, if you’ve been lucky enough to visit a zoo or watch a nature documentary on TV, you might already know about some other animals that can glide. There are gliding squirrels, gliding lizards, gliding frogs, and even gliding snakes! But one thing that all of the gliding animals we know of so far have in common is that they have some kind of special body shape that they use for gliding. Gliding squirrels have a big stretchy flap of skin between their arms and their legs which they can stretch out like a hang-glider. Gliding Draco lizards have special ribs with skin flaps between them that they can extend out from their body to make a wing shape. Gliding frogs have stretchy skin between their toes which they use to glide, and gliding snakes flatten out their entire body to make a wing shape. All of these animals are very cool, and I can tell you more about them later, but you may have noticed that all of them have some kind of stretchy part of their body that they use to make a wing shape and help them glide. The gliding ants that Dr. Steve Yanoviak discovered don’t have anything like that – they look like this:

This is a Cephalotes atratus worker which I found today up in a tree. Here she is from a different angle:

What’s weird about the fact that these ants glide is that, unlike all of the other gliding animals we know of, they don’t seem to have any wings or body parts that can be made to look like a wing if they try.

So between now and next time, think about what you would do if you found an animal that could glide and you didn’t know how they did it – how would you try to work out how they glide? What parts of the Cephalotes atratus ant’s body do you think might be most important for gliding? If you’re having a hard time thinking of ideas, try and draw a picture of an ant on paper and then cut it out with scissors. When you drop it, what happens? Does it flip over? Does it spin? Can you bend any of the parts to change what happens when you drop it? If you do this as a group, try and see what happens if half of you make ants with short legs and half make ants with long legs. Which ones are better, or are they the same?

If you’re having a hard time making a paper ant that glides, here’s another thing you can think about. Look at this picture of a really big moth I saw today:

And here’s the same moth from behind:

Now, being a big moth isn’t all about being pretty – unfortunately, you’re also very tasty and lots of things want to eat you. Many delicious animals try to avoid being eaten by using camouflage to blend in with their surroundings – what do you think this sphinx moth might look like to a predator?

Mail from Vani in PS23

May 18, 2010

Dear Yonaton,

My name is Vani.  I am 9 years old.  I like many sports such as soccer.  I have 1 brother and 2 sisters.  Also, I have many friends.  They are all nice.  Can you tell me a little bit of information about yourself?  I will be happy if you do.
Mr Evangelista told me on his blog that you will be studying ants in Panama so I have a few questions for you about ants.  Where are ants mostly found?  Do all ants live in an anthill?  How long is an ants life span?  What do ants mostly eat?  Do ants have close relatives?  How do ants protect themselves?  How many types of ants are there?  These are the questions I have for you.
Good luck finding ants in the field!

A third grade student,

Dear Vani,

Thank you for your letter, and I’m sorry I missed getting to see the hard copy with all the pictures. Maybe if I ask him very nicely, Mr. Evangelista will scan the pictures in Berkeley and send them on to me so I can see them!

In answer to your questions, I am 28 years old and also enjoy many sports, like bicycling and rock climbing. I have played soccer a bunch of times, but I’m not very good at it. One time when I was playing soccer I bent my knee backwards by accident, and ever since then it hasn’t worked very well. I have one brother, who is three years younger than me and has red hair. Even the hair on his arms and legs are red! His name is Doctor B.N. and he is mostly nice.

Your questions about ants are all very good! Ants are found almost everywhere, although they don’t like cold places like Antarctica, and they need oxygen like we humans do, and so can’t live underwater. Not all ants live in an anthill – the ants that I study, called Cephalotes (which sounds like SEH – FAH – LOW – TEES) all live in trees, usually inside dead branches. Beetles eat the wood in the branches and make tunnels, and then the ants move in and make it into their home! Some of the ants that I study live in small nests, with only a few hundred ants in each one, and some live in big nests with over 20,000 ants! That’s a lot of ants, but it’s a small nest compared to the ones that leafcutter ants live in, where there are usually millions of ants. Here’s a not-very-good photo that I took of some leaf cutter ants here in Panama – see how one is carrying a little piece of a leaf?

You might be thinking that it’s carrying that leaf because it wants to eat it, but that’s not quite true – trees don’t like having their leaves eaten, so they try to make sure they taste really bad. The leaf cutter ants don’t like the leaves, but they have found a fungus (mushrooms like what you put on pizza are a kind of fungus) that does! The fungus eats the leaves that the ants bring, and the ants eat the fungus, which they think is tasty.

Other ants that are very common here in Panama are army ants, and they never stay in the same place for long. They move their entire colony from place to place, and wherever they stop they make themselves a nest constructed entirely out of ants! It’s like a human pyramid, except way better:

That big brown thing is all ants! Here’s a close-up:

As for how long ants live, that depends on both what species of ant you’re talking about, as well as the job that that ant has in its colony. The queen ant is the boss of the nest, and makes all the new ants – she can live for many years in some species of ant. The workers don’t live as long, usually just a couple years or so and sometimes less.

Ants eat all kinds of things! The ants I study, Cephalotes, like to eat bird poop. The leaf cutter ants like to eat fungus. And army ants, well, they eat just about everything that moves. They especially like big fat katydids, which are big green insects that are kind of like a fat slow cricket that doesn’t jump. Here’s a picture of a big one that I found once:

And here she is climbing on my head:

And my head is very big, so imagine how big that katydid must be! That would be a very tasty meal for a lot of army ants.

The closest relatives to ants are wasps, and scientists think the common ancestor, like their great-great-great-great-(insert lots of greats here)-great-grandmother, of all ants and wasps lived around 80 million years ago. She might have looked like this:

This is a very old fossil ant named Sphecomyrma freyi, and long long ago it accidentally got stuck in tree sap. That tree sap turned into amber, and now we can see that these very old ants had lots of things in common with both the wasps and the ants that we see in the world today.

Like wasps and bees, ants will often protect themselves with a stinger. Ants are like wasps, and can sting many times – they don’t leave their stinger behind the way bees do. One ant that is very common around here in Panama is called the bullet ant, or Paraponera clavata. It’s called a bullet ant because its sting hurts like being shot with a bullet! I have never been stung by one, but I have a friend who got stung and they said it felt like they were stubbing their toe over and over again for the entire afternoon. They are really big ants, and I try to watch out for them so they don’t sting me. Here’s a picture of what they look like:

It’s over an inch long! But don’t worry, they don’t live in New Jersey.

Other ants like to bite, and some ants like to bite and then spray acid in the open bite wound. That usually hurts a bit, but the ants usually only do that when they think they’re being attacked.

So I hope you can see that there are lots and lots of different kinds of ants – these are only a few of the species. There are over 14,000 species of ant known to science, and new species are being found all the time! If you would like to see lots of pictures of ants, the scientists at the California Academy of Sciences have a website called Antweb. It has many pictures of all different kinds of ants – you should try and find your favorite!

Thanks again for your questions, and I hope you had fun reading this! If you have more questions about ants and the tropical rainforest, please send them on to me and I will write back!