Summary: Unfortunately, the carpenter ant will not build you new cabinets for your kitchen. The carpenter ant earned its name because it builds its nests in damp, decaying wood. Its name implies wood construction, but carpenter ants can actually be damaging to wooden frame houses.
Carpenter ants, unlike termites do not eat wood. The carpenter ant uses damp, decaying wood to build its nests. Like all ants, carpenter ants are social insects that build their colonies centered around a reproductive queen. The colonies can become quite large and be sustained for periods of years. A colony must reach two or three thousand members before winged ants will venture out to form a new colony. If you see winged ants, these are the reproductive males and females and they are a good indicator that the colony has been around for awhile. If you find carpenter ants indoors during the winter or winged ants indoors during the spring and summer, the likelihood is a nest exists somewhere in the house.
Carpenter ants build colonies outdoors in old tree stumps, or in hollowed out trees. They can also build their nests in attic beams, under sub-floor insulation, in hollow doors, and window sills. The ants will start building the colony in damp wood, but might expand into sound wood. This rarely causes structural damage to the house.
The most important step to take to achieve carpenter ant control is finding the carpenter ant nest. This can be more difficult than it sounds, because the nests are often in places that are difficult to reach, like behind walls, or inside of wooden beams. Try to watch as worker ants find their way back to their nest. The ants will be easier to follow if they are carrying food, so set out some honey, jelly, or syrup to attract the ants. Do not spray pesticides around the bait, or the ants won't come to it.
The worker ants generally search for food between sunset and midnight, so you might need to use a flashlight with a red lens to pursue the ants when they are most active. They can't see red light so using the red lens will not disturb their foraging habits.
If you find an area where you suspect a nest, but it is hidden out of your view, listen for chewing sounds. This will be a dry, rustling sound. Once you find the nest it is important to treat it directly. A pest control professional can do this best because they can drill holes and apply pesticides into the nest. A pest control professional might apply a dust inside electrical outlets because the ants commonly use electrical wiring to travel, like an ant highway.
If you are patient, then you might want to try using ant baits as a treatment option. The bait systems are purposely slow acting to allow the poison to reach as many individual ants in a nest as possible before it starts working. A solution of 1% boric acid and a 10% sugar water solution can be used as homemade bait by placing the solution where the ants can find it. Monitor the bait to see if the ants are using it for food. If they are, then replenish the bait. If they are not, then change the location of the bait or try a different type of bait. Bait methods can take weeks or months to achieve control. Simply repairing or replacing damaged or rotting wood can also be effective in getting rid of carpenter ants.
To eliminate a carpenter ant problem originating outdoors it is again necessary to find the nest. These can be in tree stumps or logs, and by removing the nest you will get rid of the ants. Three gallons of boiling water poured into the nest will kill the queen and is also efficient in getting rid of carpenter ant nests.
Prevent ants from entering the home by moving firewood and mulch away from the exterior foundation walls. Prevent water from running towards the foundation by grading soil and mulch away from the house. Look for other places moisture might come into contact with wood like leaky gutters or dripping air conditioners.