Carpenter ants are some of the largest and most common ants in North America. Of the 1500 species of carpenter ants around the world, more than 50 live in North America. During their mating cycle, carpenter ants develop wings, making them appear even larger. Because they live in and are destructive to wooden structures, some people confuse carpenter ants with termites, though they are very different insects.
Carpenter ants are usually black in color, but other variations are possible. Worker carpenter ants grow as large as 1/2-inch in length. Queens can be twice that size. Carpenter ants look similar to other ants, but have two distinguishing characteristics that can help confirm their identity. The top of a carpenter ant's thorax is smooth and even. Most ant species have an uneven thorax. Additionally, carpenter ants have a single node, or petiole, between their thorax and their abdomen. Other ant species may have two petioles.
Carpenter ants build their nests both indoors and out, preferably in moist wood. It is for this reason that indoor carpenter ant nests are often found in areas that are prone to water leaks, such as inside walls near a sink or bathtub. Carpenter ants build two types of nests: parent colonies and satellite colonies. Parent colonies are home to worker ants, a queen, eggs and larvae. Satellite colonies contain no eggs or larvae, but can house many worker ants from the parent colony. With no eggs or larvae to require moisture, satellite colonies can be found in drier wood.
Because carpenter ants nest in wood, a colony will cause damage to any structure it is using for a home. The longer a carpenter ant colony is in one place, the more damage it can do. If the wood was weakened or damaged prior to the carpenter ant infestation, the damage can be very serious. Carpenter ants damage wood by creating tunnels and galleries. The ants leave the wood with a finished appearance, almost as if it had been sanded, though they leave no sawdust.
There are things that homeowners can do to make their homes less attractive to carpenter ants. Replace any wood in the home that has been damaged by moisture. Store firewood off the ground, away from moisture and away from your home's foundation. Keep wet soil from coming into contact with any wooden siding. Be sure to look and repair leaks in and around the home, especially in the attic, basement and outside near the foundation. Reducing moisture problems will give carpenter ants fewer reasons to enter your home.