Monday, November 21, 2011

I for one welcome our new insect overlords.

Why did I read a book about leafcutter ants?  It interferes with all of my important projects, the one’s where I – do – well – all of those important things I was thinking of.  I don’t remember what those things were.  Ants, why not ants?  The Leafcutter Ants: Civilization by Instinct (2011), by Bert Hölldobler and Edward O. Wilson, that’s the book.

I read the book because: a) it was on the New Books shelf at my library, b) it is short, c) it is full of hideously detailed close-up photographs of leafcutter ants cutting leaves and doing all of the other strange things they do:

Please note how the one mandible becomes a serrated knife while the other guides the path of the cut.  Please note how the foreleg lifts the severed edge of the cut.  Please note how horribly spiky the ant is.

Millions of leafcutter ants, all over South and Central America, are as I write sawing up vegetation, which millions of other ants carry back to their enormous underground fungus farms, where millions more tiny, specialized ants carefully dismember the plant fragments and feed them to the symbiotic fungus, while other tiny ants harvest the fungus to feed the hive.  Other parasites and symbiotes wander through the system.  It is all so wonderfully strange.

A team of Brazilians researchers have become leafcutter nest archeologists, specialists in “the megalopolis architecture of Atta colonies” (115).  They pump a nest full of liquid cement (for one particular nest, over 6 tons of cement), and then excavate the ant city using standard archeological techniques:

One reason to read a book like this is to witness the creativity of scientists.  There are so many kinds of creativity.

The little leafcutter ant book is an expansion of a chapter of another recent Hölldobler and Wilson book, The Superorganism, which is presumably packed with forbidden knowledge beyond the ken of mortal man.  The leafcutter ants, though, are “the greatest superorganisms on Earth discovered to the present time” (127).  That last qualifier scares me.

This schematic of a leafcutter ant brain is just a bonus illustration for 50 Watts, who likes this kind of thing, as do I:

If you have a niece or weird uncle who is into zombies, get them this book for Christmas.  They will be furious at first, but they’ll enjoy it and will thank you, perhaps many years later.


  1. I've been meaning to read about ants for a long time, ever since I saw them impressively at work in Costa Rica. The rain had stopped. It was nearly silent, just a bit of rainwater dropping from the trees. Like a fire brigrade, an industrious line of leafcutters stretched from my feet to Somewhere. I got on my hands and knees and marvelled at them. When you get that close, you can hear them marching over fallen limbs and forest duff. And once you hear them, you continue to hear them even after you stand up, like a constant buzz. How do the authors define a superorganism? Cheers, Kevin

  2. Good question. Let's see. "[T]he entire colony represents an extended phenotype of the queen and her mates on which evolutionary selection operates" (9).

    I like this one better - it's more provocative: "They are civilizations designed by natural selection to replicate themselves in as many copies as possible before their inevitable death."

    The parent book, The Superorganisms sounds fascinating, too, but it is a behemoth. Reading the ant book was an achievable task.

  3. Think I might read it. The achievable one that is. That first definition might break down if mates compete for access to the queen. One mate, call him Stubs, might have an advantage over others, which gets passed on, etc.

  4. You understand this well. The co-authors disagree on the definition of "superorganism" around what I think is more or less your point. See p. 126, right at the end.

  5. It's not our insect overlords, it's our corporate overlords: wouldn't these ants be the ideal citizens of the world the corporate giants are trying to herd us into? And any ants that misbehave will be sprayed.

  6. "If visitors from another star system had visited Earth a million years ago, before the rise of humanity, they might have concluded that leafcutter colonies were the most advanced societies this planet would ever be able to produce. Yet there was one step to take, the invention of culture, making it possible to write this book about them."

    The ants do not misbehave.

  7. Whoah, those are some serious ants! Gave me the crawlies just looking at the photo. So, one question, was that colony the scientists pumped full of cement empty of ants when they did it or did all the little critters find they suddenly had cement shoes? They may give me the crawlies but they are a vital part of the ecosystem and it would be tragic if a whole colony was wiped out like that.

  8. Nope, the scientists croaked the ants. South American farmers wipe out ant nests all the time.

    Leafcutter ants are not exactly an endangered species in Brazil - more like the dominant species. Humans live among the ants.

  9. A schematic of a leafcutter ant brain just for me! Thank you.

  10. My pleasure. This is a book with a great deal of visual interest.

    To anyone who does not know why I thought Will would enjoy this image, please make your way to his biology textbook page. Set some time aside. So worth it.