Small black ants found in the United States are likely to be carpenter ants of the species Camponotus pennsylvanicus. They range in size from 1 to 2 centimeters and have a dull black body with white or yellow hairs on the abdomen. Workers are wingless while breeding males have wings.
Carpenter ant colonies typically have 1,000 to 3,000 female workers, a single queen and 200 to 400 breeding males. The worker ants are born sterile, leaving only the queen to incubate eggs during breeding season. All ants in a carpenter colony have only one function: workers find food, and queens and males breed.