Mature carpenter ant nests will contain about 3000 ants and can occupy a very large area.
Carpenter ants can enter structures in a number of ways. A single queen can enter the home and begin laying eggs. An entire colony can move in using telephone or hydro lines, fences, tree limbs touching the house or simply march across the lawn and up the side of the house. Another way is through firewood. Carpenter ants become dormant in the winter. If infested wood is brought in, the dormant ants can revive when the wood warms up, and possibly move into the structure of the house. Stumps, dead limbs, rotting decks, fences, railway ties and firewood are some common sources in the yard. Eliminating carpenter ants involves finding the nest. Watching for areas of heavy activity, observing where the ants go in and out of the woodwork, listening for noises made by the colony, looking for sawdust piles and watching for activity on the exterior are all ways of trying to determine the nest location. Check for areas that may have a moisture problem such as leaks around tubs or showers, leaking plumbing, roof leaks, leaks around windows, etc.
Carpenter ants are mainly nocturnal and activity peaks during the night. They are most actiVe in warm, humid weather and less active when it is cool. All ants produce a winged stage at a certain time of the year. These are the reproductive stage or Kings and Queens. Carpenter ant reproductives emerge in late spring or early summer. This stage is only produced in well established colonies. It is possible to have more than one nest especially if the ants have been there for a long time. We have inspected homes with multiple nests scattered throughout the house. Prevention of carpenter ants involves eliminating moisture problems, pruning back tree limbs touching the house, removing rotting wood from decks, fences, tree stumps or other sources such as railway ties and firewood close to the house. Treatment of these ants often involves drilling small holes into the nest area and injecting insecticide into the nest. In some cases it may be necessary to pull off trim or paneling to get to the colony. Treating around the outside perimeter will also help.
Although carpenter ants can severely damage a section of wood such as a window sill, beam or stud, especially if it has been water damaged, they will not cause the house to come crashing down around you. Their damage is usually confined to relatively small areas. Well established colonies however can be a major annoyance with large numbers of ants roaming through the house each spring and early summer.