Carpenter ants belong to the Camponotus genus, and many species can be found throughout the United States, some of which are pests of homes. Carpenter ants get their common name from their habit of nesting within moist and decayed wood, such as tree stumps, logs, fallen branches and tree hollows. A few species like the black carpenter ant and the western carpenter ant are known for occasionally nesting within structural lumber in homes. Since carpenter ants nest within moist wood, their presence in homes can indicate moisture problems, such as plumbing and rainwater leaks. However, most carpenter ant pest species do not establish nests within structural wood, and most carpenter ant infestations see workers invade homes from outdoor nests. According to a recent nationwide survey of pest control professionals, carpenter ants were the most commonly managed ant pests within homes during 2016.
Carpenter ant workers are noticeably large in size, as they are around half an inch in length, and queens usually exceed ¾ inch in length. Carpenter ant workers leave their nest to forage during the afternoon and late night to early morning hours. Carpenter ants originate from one “parent nest” that is always located in outdoor wood, but foraging workers establish several secondary nests, or “satellite nests” located at varying distances around the parent nest. It is not uncommon for carpenter ant workers to establish satellite nests within homes, but this does not mean that workers establish nests within structural wood.
Workers often establish indoor nests within wall voids where structural wood is located, but they do not always nest within available structural wood sources because the environment within wall voids is often moist and dark enough to meet the biological needs of workers. The western carpenter ant (C. modoc) is the carpenter ant species most likely to nest within structural wood, but they rarely establish more than two indoor satellite nests. Professional pest control intervention is necessary when carpenter ants establish indoor nests, as exterminating nests within wall voids requires special insecticide dust formulations that are not available to consumers.
Have insect pests ever congregated within walls in your home?