Flagstaff, AZ – Earth Notes: Carpenter Ants
Take a break on a fallen tree during a hike through a ponderosa forest, and you might want to take a closer look at where you're sitting. Chances are you're not alone: you might see a large ant or two walking along the log.
These champion excavators are carpenter ants, some of the roughly thousand species of ants found worldwide. Two species of carpenter ant are commonly seen in northern Arizona. One is all black, while the other has a red thorax or midsection. Either way they are easily distinguished by their large size, about a half-inch long.
A single colony, which might contain thousands of workers, can stay in the same comfortable wood nest for up to ten years. Unfortunately, carpenter ants don't distinguish between a home in the forest or under your house.
"They can cause significant damage," says Dr. Sky Stephens, a researcher with Northern Arizona University's Entomology Lab. "You can hear them at night as they excavate. They sound like a bowl of Rice Krispies."
Carpenter ants don't eat the wood but remove it, tiny piece by piece, then take it outside the nest and dump it on a growing pile of sawdust.
While they might be harmful to wooden structures, these large ants are important in breaking down woody material. Their excavations in snags can be extensive enough to weaken and topple a dead tree.
"Wood decays slower here in arid climates," explains Stephens. "Carpenter ants help the decay process go a little faster."