According to numerous research studies and multiple nationwide surveys of pest management professionals, carpenter ants are the most commonly controlled ant pests in residential areas in the US. Ants belonging to the Camponotus genus are commonly referred to as “carpenter ants” due to their habit of nesting within moist and decayed wood sources such as logs, stumps, fallen branches, and occasionally, structural wood within homes and buildings. However, not all Camponotus ant species nest in wood; instead, a large number of species establish nests solely in moist soil, and wood-nesting species also regularly nest within soil, as well as in plant debris and moist enclosed spaces.

Of the more than 1,000 carpenter ant species documented worldwide, only around 20 are known to be indoor pests in the US, six of which are considered common, and only three of which are known to inflict costly structural damage by nesting within woodwork. The most commonly controlled and destructive carpenter ant species in the country, C. pennsylvanicus, is found throughout the eastern US and several western states, but this species is most prevalent in the northeast.

pennsylvanicus is commonly known as the “black carpenter ant,” and like most carpenter ant species, black carpenter ant workers are noticeably large in size and are often spotted marching in formation within homes in order to secure food sources. Carpenter ants are notable for eating a variety of foods including sweets, meats, grains, and it is not uncommon to find the pests infesting cupboards and pantries.

Carpenter ant colonies start out as a single outdoor nest located within wood, but as colonies grow in size, workers leave the “central nest” in order to establish small “satellite nests” nearby. It is not uncommon for black carpenter ant workers to establish satellite nests within moist indoor structural wood components hidden within enclosed spaces, most commonly wall and ceiling voids where moisture levels are relatively high.

Unlike termites, carpenter ants do not eat wood, but they are similar to termites in that they excavate nesting galleries within structural wood components, resulting in costly damage, and in advanced infestation cases, structural breaks. Surprisingly, carpenter ant infestations often become noticed after residents hear rustling noises within wall voids. This is the sound of carpenter ants plowing through wood. Knocking on walls will disturb the ants, prompting them to rustle about more violently, and more loudly. In order to eliminate a carpenter ant infestation, all indoor and outdoor satellite nests, as well as the central nest must be located and destroyed. This is a tall order for homeowners, as specialized equipment is generally necessary to pinpoint carpenter ant nesting sites within wall voids. Most carpenter ant infestations require professional pest control intervention.

Have you ever heard the rustling sounds of carpenter ants within your walls?