What are Carpenter Ants?

Mary McMahon
Mary McMahon

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.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a wiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

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Discussion Comments


I once had a couple leaks in a house I lived in. The ceiling wouldn't leak every time we got rain. The rain had to fall in a certain way -- hard and driven by wind. When the rain fell this way we would see the water leaking through the ceiling.

When a roofer came out and checked the attic, he found that the roof had been leaking more than we thought. The water just hadn't been seeping through the ceiling all the time. There was plenty of damaged wood in the attic, and yes there were carpenter ants. The water had caused more damage than the ants had, but it is a good idea to check your attic from time to time to make sure there are no leaks.

We had seen the winged carpenter ants from time to time down stairs, but at that time I had no idea this meant we had carpenter ants nesting in the house.


I agree with the article that boric acid is good for controlling carpenter ants. I have found that when I add sugar and create a mixture of the sugar and boric acid the ants are more attracted. Once they reach the bait they take it back to the nest and usually they are gone before long.

Actually, boric acid and sugar is good for carpenter ant extermination and any other type of ant extermination. I have sprinkled the mixture on fire ant hills and it kills them. With the bigger mounds you might have to reapply the bait a few times, but eventually the ants disappear.

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