This book, written by Bert Holldobler and Edward O. Wilson, the same men who wrote The Ants, is an improvement in many ways. Some of this is due to technology. The Ants simply lacked as many great photos as The Leafcutter Ants, but 20 years of progress in photography is a lot. There likely was also more information about leafcutter ants available due to more research having been done and published during those years. But mostly the improvement is that this book, while still very technical and dry at times, was much more readable and much more digestible than the massive book about all ants. There was a large section about leafcutter ants in The Ants, but this really went into depth in ways the other had not.

Leafcutter ants have some of the largest colonies, extending well into the millions and excavating large areas of soil underground. They typically harvest leaves from trees or grass, depending on the species, chew up the leaves into small chunks, fertilize them with feces, and then grow a specific fungus inside their nests.Every ant colony is surprisingly complex; more complex than you would consider, but leafcutter ants might be the most complex, and that is probably why the authors chose to write a book only about them.

Some of the most interesting information I learned was about how the mutualistic fungus grown by the ants seems to communicate with them in some unknown (at least at the time of publication) methods. For example, plant material laced with toxins first gets collected by the ants, but after several hours, they reject it. They reject it so wholly that they won’t collect the same type of plant material even if it isn’t laced and they continue to reject it for many weeks. Another really cool feature is that the ants even have special structures in their bodies designed to house bacteria that produce chemicals that suppress the growth of fungi harmful to the type of fungi they grow. Probably my favorite bit of information relates to how ants often stridulate (make rhythmic vibrating sounds), and leafcutters apparently adapted this behavior to help them cut leaves. It seems vibrating rapidly helps them cut leaves like a saw. It is pretty wild how involved and complicated the ants’ behaviors and physiology are to the growing of fungi and I only gave three of my favorite ways.

My biggest complaint about this book was that the authors really stuck to their guns when it came to focusing on leafcutter ants. There are many species of leafcutters covered, but the Holldobler and Wilson revealed tantalizing information about closely related species that grow fungus on detritus, or that grow yeast instead of fungus. I thought a couple more pages on those cousins would really help me better understand the evolution to–and potentially away from–leaf cutting.

In conclusion, this book has great balance of being in-depth, technical, and readable, making it a very digestible way of learning a lot about this relatively small group of ants. I learned a lot, recalled more, and enjoyed the experience.