01:00 AM EDT on Sunday, September 18, 2005

BY JAY ROMANO
New York Times News Service

Contrary to popular belief, carpenter ants will not eat your house. They might, however, move some of it out of their way.

"Carpenter ants don't cause nearly as much damage as termites," said Mike Potter, extension entomologist for the University of Kentucky College of Agriculture in Lexington. "But they certainly are a nuisance, and they can damage wood by hollowing it out for nesting."

Potter said the most common type of carpenter ant in the Northeast -- Camponotus pennsylvanicus -- is one-quarter to one-half inch long and "blackish." Occasionally, he said, swarms of winged carpenter ants will emerge inside in the spring -- an almost certain sign that there is a nest in the house.

It is also possible, Potter said, that homeowners will see a small number of ants wandering around the home -- usually in the kitchen or bathroom -- and that the nest is outside the house and the ants are foraging inside for food.

UNLIKE TERMITES, which live in the ground but eat wood voraciously and can do considerable damage, carpenter ants prefer to establish their nests in hollow areas and inside moist wood. Rather than eating the wood, they excavate it to create smooth-walled, hollowed-out galleries.

The excavation process results in a telltale sign that a carpenter ant nest is nearby. "Shredded fragments of wood are ejected from the galleries by the ants," Potter said. Sawdustlike piles intermingled with dead ants and other insect parts often point to a nest just above.

But if the nest is inside a wall, the sawdust pile is not going to be noticeable. Moreover, carpenter ants typically have several nests: a parent colony that contains the egg-laying queen and worker ants, and satellite colonies with workers and babies.

"The parent colony is usually outside, inside a rotting tree stump, broken limb or wood pile," Potter said. "But there could be one or more satellite colonies inside the house."

THE DAMAGE caused by carpenter ants depends on how many nests are inside the house and how long the ants have been active. So, Potter said, the best way to control carpenter ants is to find and destroy the nests. "Unfortunately," he noted, "this is easier said than done."

Indeed, unless there are sawdust piles, the only way to find the nest is to let the ants lead you to it. The best way to do that, Potter said, is to place bait -- small dabs of maple syrup or honey on the nonsticky side of tape works well -- in areas where ants have been seen. Once the ants have taken the bait, they can be followed to their nest. "They'll gradually wind their way to the nesting site," he said.

TRADITIONALLY, he said, carpenter ant treatment involved applying insecticide directly to the nest. And it often was necessary to drill small holes to where the nest is suspected and inject the treatment inside. "For homeowners, boric acid dust is probably the most available," he said.

Potter noted, however, that more effective and easier-to-use carpenter ant treatments have recently emerged on the market.

Tommy Powell, owner of Professional Pest Control Products in Pensacola, Fla., a distributor of pest control goods (www.pestproducts.com), said one effective indoor carpenter ant treatment is Maxforce Carpenter Ant Bait Gel, an insecticide marketed primarily to professionals. "It has a mixture of attractants carpenter ants like," he said.

The bait, which comes in a plastic syringe, can be injected into cracks or crevices where ants are seen but out of reach of pets and children. The ants then take the lethal booty back to the nest, where it is shared. "Homeowners should check with local officials to determine whether specific pest control products are permitted," Powell said.