Carpenter ants are large ants in the genus Camponotus, found in many regions of the world. They prefer to nest in wood, as their name suggests, and although they do not eat wood, they can severely damage structures and trees by hollowing out wood to nest in. Because of this tendency, carpenter ants are largely regarded as a pest, and many people eradicate them if they are detected in or around a home.
These ants are among the largest of ant species, with both winged and wingless individuals. The presence of winged carpenter ants in a home suggests that the nest is very close by, and possibly in the home. Wingless individuals and small groups of ants indicate that the ants are searching for food in a home, but not necessarily nesting there.
When carpenter ants nest, they hollow out a series of tunnels in wood. They prefer moist wood, and can often be detected by the small piles of sawdust they leave near the entrances to their nests. Carpenter ants establish both main and satellite colonies, which vary widely in size. They are also, in an interesting side note, colonized by symbiotic bacteria, with the ants providing food for the bacteria, and the bacteria generating essential amino acids for the ants.
The issue with carpenter ants in the home is that they can damage a structure, potentially creating a dangerous situation. People can reduce the risk of colonization by controlling leaks and sources of dampness, eliminating soil to wood contact, and keeping shrubs and trees well trimmed around the house. Rotten, wet, and damaged wood should be removed and replaced promptly so that it does not become a temptation to carpenter ants. Ideally, potential nesting sites such as tree stumps should also be eliminated from the area in close proximity to the home.
If carpenter ants are spotted in the home, many pest control experts recommend following them to find out where their nest is. Nests can also be pinpointed by tapping gently on the walls around a suspected nest: a hollow noise typically results, and a rustling noise may be heard as the disturbed ants scurry inside the nest. If a nest is found, boric acid powder or another insecticide can be introduced to it to kill the ants before removing the area of damaged wood and replacing it. Ant baits can be used to kill carpenter ants when a nest cannot be found. Make sure to keep insecticides out of the reach of children and pets, and consider consulting a pest control expert or a contractor if you have difficulty dealing with carpenter ants.