Carpenter ants are some of the most noticeable ants. This is due to their large size, ranging from around a quarter of an inch to a full inch in length depending on the species. Most commonly black, they can also appear reddish or yellowish. Like termites, they form extensive colonies in dead wood and can be a serious and costly problem for homeowners if they are not controlled.

Preferred nesting locations for carpenter ants can be found both indoors and outdoors, specifically in moist dead wood. Within this wood they form what are known as primary and satellite nests. After her nuptial flight, the newly-fertilized queen ant will excavate a primary nest. The primary nest will house the queen and eggs, as well as newly hatched larvae and eventually the caretaker worker ants. These nests are typically created in areas of high humidity, which is required for proper survival of the eggs. Once the larvae have matured some, however, they are relocated to the satellite nests. Satellite nests are typically in much drier locations, as they do not house eggs. There can be more than one queen within a colony, but they maintain separate territories within the colony and will fight any invading queens. These colonies can contain up to 50,000 ants.

Because of their preference for moist, dead and decaying wood, carpenter ants are actually an important part of proper forest decomposition. However, they do not eat the wood, as termites do; they are simply woodworkers. Many of the tunnels these ants create in the wood lead to or from a food source, one of their favorites being honeydew created by aphids. Like most ants, they will actually care for aphids so they have access to this sugary substance. Dead insects are their other main food source, with most foraging done individually, and at night.

While they do not eat wood, their tunnel excavation can still cause serious problems for homeowners. Here in Wisconsin, it is actually more common for structural damage to be caused by carpenter ants than termites. However, this damage might not be apparent until many years have gone by. The easiest way to identify a carpenter ant infestation is sawdust-like piles around the home. Areas that are most prone to infestations are decks, porches, under windows and around roof eaves.

Did You Know?
If ants are seen within the home during winter or early spring, this is likely a sign that an infestation exists.