Carpenter ants are the common, large black ants (1/4 to 1" in length) that everyone has seen. They are polymorphic, meaning the workers can come in different sizes.They nest in wood, but do not eat the wood for food the way termites do. They chew tunnels and galleries in wood (preferably moist or partially rotted) for a nest area, toss the wood chewing out of the nest sometimes resulting in a pile of sawdust. How destuctive they are will depend in large part on where they build their nest. If they nest in a wall stud, or window frame, they probably won't do any significant damage, but if they get into a carrying beam, a door sill, or foundation sill they can do significant structural damage. They used to be notoriously hard to treat, unless the nest could be found, but today with new undetectable pesticides that job has become much easier. Don't use over-the-counter outside "barrier" teatments because they act as repellents, and if the nest is in the structure of the house, the ants now can't get outside, and the problem inside becomes worse! They do not respond well to "Hardware store" ant traps or sprays, so it is usually a waste of money to even try. A professional should be called in, because they have the experience of knowing likely nesting areas. Carpenter ant prevention can be accomplished by:
1. Storing firewood off the ground and at least 75' from the house.
2. Correcting any moisture problems within the house such as soil to wood contact, clogged gutters, leaking pipes, or condensation
3. Removing any broken, decaying, or dead trees or branches, and stumps within 75' of the house.
4. Trim all shrubbery and vegetation back at least 12" so they are not touching the structure!
Death of a carpenter ant nest
Damage to Styrofoam insulation under siding
Carpenter ant nest above screen on a porch
Damage to header above a garage door
The same nest after treatment