Carpenter ants vary in size and color but are usually large (1/4-1/2 inch) and blackish.
You may see worker ants travelling through rooms in search for water or food, or winged ants flying in hopes of escaping to the wild.
Occasionally, winged ants will swarm inside a home.
This usually happens in the spring and are a sure sign that a colony has been nesting somewhere inside the structure.
Most carpenter ant infestations are small in number, generating only 20 or 30 swarmers.
But this population can grow as the ants look for a warm place to spend the winter.
If you see more than a few winged black ants in or around your home, steps should be taken to get rid of them before they become a more serious problem.
Carpenter ants forage for food within great distances of their nests, and may establish outposts in a number of different locations - both inside and outside of a structure.
Worker ants can travel up to the length of a football field looking for food.
They construct two different kinds of nests.
Parent colonies mature to contain an egg-laying queen, her brood and 2000 or more worker ants.
Satellite colonies, on the other hand, may have large numbers of worker ants but no queen, eggs or young larvae.
The carpenter ants inside a home may have originated from the parent colony or from one or more satellite nests.
For example, the ants may be coming from the parent nest located outdoors in a tree stump, landscape timber or woodpile, or from one or more satellite nests hidden behind a wall in the kitchen or bathroom, or perhaps from wood dampened by a roof leak in the attic.
The first sign of a carpenter ant infestation is usually the sighting of numerous workers throughout the home.
Indoor infestations can be tracked by points of entry such as attic vents, foundations, cracks, electric wires, pipes and telephone lines.
They prefer to nest in structural lumber such as wall voids, hollow doors, windows and foam panels.
They typically seek wood that has been softened by moisture, decay or other insects.
A positive indication that an active, mature infestation is present is the emergence of large winged ants from walls, ceilings, or crawl spaces.
The mess they leave behind while building their nests often remains hidden behind a wall or in some other concealed area.
In addition to structural lumber, sites such as hollow-core doors, window headers, wall voids, and foam panels are particularly attractive to carpenter ants.
Although these ants do not intentionally destroy wooden structures, they are capable of damaging any wood within which they nest.
The infestations can become severe when left untreated, and in some cases, a colony of carpenter ants can develop satellite nests.
In order to control an infestation, it is important to identify carpenter ants and their nests.
Worker carpenter ants are active mostly at night, so you may not see any activity during normal working hours.
Probing the wood with a screwdriver helps reveal the excavated galleries.
Another technique for locating hidden nests is to tap along baseboards and other wood surfaces with the blunt end of a screwdriver, listening for the hollow sound of damaged wood.
If a nest is nearby, carpenter ants often will respond by making a clicking or "rustling" sound within the nest, similar to the crinkling of cellophane.
You can also use a stethoscope to listen to sounds of carpenter ants deep within your walls.