Carpenter ants live in large colonies with hundreds of workers (all sterile females), several males and females that reproduce, and one or more queen. When part of an established colony goes into a nearby structure, it sometimes establishes a smaller satellite colony there. Some experts believe this is the main way carpenter ants invade houses.

Carpenter ants don’t actually eat the wood they excavate (unlike termites), lacking the digestive enzymes to break down cellulose. Instead, they forage on a wide variety of plant and animal materials, including sweet substances, like honeydew produced by aphids. They also eat the body fluids and proteins of both dead and live insects. Most of this foraging is at night, kept somewhat hidden by the underground tunnels they use. Carpenter ants have a painful bite, but cannot sting.

Hilltopping: When the winged swarmers emerge in spring to mate, they often gather at pronounced points on the landscape, like a large tree or lone building or top of a hill, thus the term, “hilltopping.” The swarms can turn into rolling clusters of males trying to mate with a single female.

Exploding ants: Some Malaysian carpenter ant species make the ultimate sacrifice to defend against attackers. They can explode their bodies, spraying a sticky and caustic fluid from inside a special jaw-to-abdomen-length gland, which immobilizes the enemy.