Other wood-destroying insects
Carpenter ants are also social insects. They live in colonies with a rigid caste system consisting of a queen, workers, and reproductives (sexually mature males and females that periodically swarm and set up new colonies). Although worker ants can live four to seven years and the queen for as long as fifteen, colonies have been known to last for thirty to forty years. When the queen dies or is accidentally killed, specially fed workers take over the egg-laying function.
Carpenter ants differ from termites in that they do not eat wood. They merely excavate it to build a nest. The nest consists of irregularly shaped galleries that generally follow the grain. The small fragments of shredded wood that are generated during the excavation are removed from the galleries and deposited on the outside. Consequently, the galleries do not have the earthy appearance of the termite galleries. Rather, they have a polished or sandpapered appearance.
A carpenter-ant colony can be located on the ground in a decaying log or tree trunk or in the roof framing of a house. The ants also nest high in trees and can fly from there to set up new colonies in a house. They build their nests in a variety of locations, preferring wood that is moist or softened by decay. However, they will also build their nests in wood that is perfectly dry and sound.
When inspecting for carpenter ants, look specifically at sections of wood that have begun to decay as a result of a past or current moisture condition. Even though the source of the moisture might have been eliminated (as by correcting a leak), an ant colony might have been established already. Typical locations to inspect are portions of the wood framing, siding, or trim that are in contact with the ground; wood that has been dampened by the overflow from defective roof gutters; the area around a damaged section of siding or flashing; the base of hollow porch posts and columns, and areas with large open joints as might occasionally be found around exterior windows and doors. These areas should be probed with a screwdriver or an ice pick. If the wood yields, breaks, or cracks and ants come crawling out, there is a good chance that you have located a nest.
Consider yourself lucky if you do, because a carpenter ant nest is usually quite difficult to locate; it is often established in an inaccessible location in the wall or roof assembly. One indication of the existence of a colony is unexplained piles of sawdust. Some people, however, think that piles of sawdust are an indication of termites. They are not. Subterranean termites completely devour the wood that they are attacking and leave absolutely no trace of wood particles. Dry-wood termites also eat the wood completely. However, they do drop tiny, well-formed seedlike pellets. If the pellets are observed closely, they can be differentiated easily from irregularly shaped particles of sawdust.
When a house is infested with carpenter ants, there is little likelihood that the people living there are unaware of the condition. Numerous worker ants will be seen walking around the rooms as if they live there- which indeed they do, with free room and board. These ants feed on sweets, crumbs, and other foodstuffs normally found or spilled on a kitchen counter or floor. Carpenter ants are easy to recognize. They are among the largest ants in the United States, worker ants varying in size between 1⁄4 to 1⁄2 inch long. They are black or black with a reddish brown midsection.
While the first sign of infestation is usually the presence of carpenter ants in the house, the fact that they are there does not mean that the nest is inside the house. It might be outdoors, and the ants may have entered the house foraging for food. A carpenter-ant infestation can be controlled only by destroying the nest, either directly or indirectly. Nests can sometimes be located by watching the ant traffic. Ants continually entering and leaving an area are generally an indication of the nest location. If the nest is found, it can be treated directly with insecticide. If not, dusts or sprays can be used where the ants are commonly seen. The latter might not eliminate the infestation, but it should reduce it.