One of my favorite past times is flipping rocks. It sounds boring, I know. Maybe not something to suggest on a first date, but by the third date or the fourth? It’s a possibility.

For me, flipping a rock is like unwrapping a present. There is an element of surprise. Once, there was a tiny rattlesnake coiled beneath a rock in Arizona, and I gently set the rock back down. Usually though, I’m hoping to find ants.

So last week when our field specialist Melissa Burt said, “I think I found something,” I quickly stopped what I was doing and went to take a look. Melissa pulled back a rock to reveal a colony of fungus-gardening ants, and what was especially exciting was that their fungus garden was in full view.**

Trachymyrmex septentrionalis fungus garden. Photo credit: Clint Penick

Trachymyrmex septentrionalis fungus garden. Photo credit: Clint Penick

Most fungus-gardening species are found exclusively in the tropics, but just one species, Trachymyrmex septentrionalis, makes it up to North Carolina. The tropical species are famous from nature documentaries and TV specials as the “leaf-cutters,” which march in long trails carrying fresh-cut leaves above their heads. The ants don’t eat the leaves themselves, but instead, they feed the leaves to their developing fungus gardens. Like our own crops, the fungus is what serves as the ants’ primary food source.

When our own species invented agriculture in the Fertile Crescent about 10,000 years ago, it led to the development of cities and eventually to the huge societies that now dominate most of the planet. Likewise, fungus-gardening ants produce some of the largest colonies in nature, and they have developed complex infrastructure like highway systems and nest ventilation structures.

Our native fungus-gardeners are less conspicuous, and their colonies are usually small and sometimes hard to find. Rather than cut fresh leaves, they cut flowers or even use caterpillar frass to grow their fungus gardens. And while they may seem less impressive than their tropical cousins, they have one major advantage: you can actually see their fungus gardens. If you want to find the fungus gardens of a large tropical colony, you have to rent a backhoe, but with Trachymyrmex all it takes is the effort to lift a rock. You may have to lift a lot of rocks, but who knows what else you might find.

**For the record, we found this colony at Lake Johnson Park right near NC State campus. For other cool ant discoveries in the city, check out the School of Ants page.

And remember, we always want to hear about the moments of nature you observe in our backyards and neighborhoods – Drop us a line at!