After three years or more, winged males and females are produced, and they engage in nuptial flights. Millions of dollars are spent annually to control carpenter ants in the United States. There has been conflicting information regarding whether or not carpenter ants attack new, undamaged wood. Current information has shown that colonies are first established in pre-existing cavities, usually in faulty or rotten wood, then expand into both rotting and undamaged adjacent wood around such cavities. They do not eat wood or tunnel through wood structures as do termites.
Damage is local, caused by enlargement of the nest.
Colonies may be composed of thousands of workers of various sizes, winged reproductive forms, and immature ants. Homeowners may see individual ants, but may also note the presence of carpenter ants by finding a pile of coarse sawdust, commonly mixed with ant and other insect parts, on the carpet or other floor surface in the house. Carpenter ants do not usually bite humans, but their jaws are large and capable of inflicting a painful bite. Carpenter ants do not sting. Workers are omnivorous, and will attack live arthropods as well as scavenge on dead arthropods for proteins.