How to Get Rid of Carpenter Ants in Your Long Island Home

Because there is wet wood somewhere, and probably has been for a while. University of Minnesota Extension says that in homes, parent nests are found in moist or decayed wood caused by water leaks, condensation, or poor air circulation, and Penn State says these ants seldom tunnel into dry, sound wood. The ants did not cause the problem. A leak under a window, a roof edge that stays damp, a deck ledger, or a bathroom wall did, and the ants found it.

Timing matters for the diagnosis. Minnesota says seeing carpenter ants indoors during winter means there is an inside nest. Kentucky's fact sheet says a carpenter ant swarm indoors, usually in spring, is a sure sign a colony is nesting somewhere inside the structure, and Penn State notes a colony does not produce winged males and queens until it is several years old with about 2,000 to 3,000 workers. Winged ants on the inside of your window in April means the nest has been there for years.

Two reasons. First, it only kills the ones you see. Utah State's fact sheet says killing workers or swarming ants is generally ineffective because a healthy queen will soon replace them, and Minnesota says spraying foraging workers may temporarily reduce the number you see but will not eliminate a nest. Second, repellent sprays move the problem. NC State: although spraying stops ant foraging for a while, it only serves to repel and send them elsewhere, possibly elsewhere indoors, and they will likely return when the residue is gone.

There is a third cost. Spraying destroys the evidence. Kentucky's advice is not to spray when you see carpenter ants but to feed them small dabs of diluted honey on masking tape and follow them home. The trail is the map to the nest.

Follow the ants at night, and look for the sawdust. Minnesota says they search for food between sunset and midnight in spring and summer. Kentucky describes the frass: shredded wood fragments like coarse sawdust ejected from the galleries through cracks or slits, typically containing dead ants and bits of insects, and says an accumulation of it means a nest is nearby. Tap along baseboards and trim with a screwdriver handle for the hollow sound of damaged wood; Kentucky says a disturbed nest often answers with a rustling sound like crinkling cellophane.

Then look outside. Penn State says the parent colony is often in a tree, log, or waste wood within 100 yards of the house, with satellite nests inside. Kentucky lists tree stumps, landscape timbers, and woodpiles. Penn State is clear that to eliminate the ants, the parent and the satellite nests must both be found and eliminated.

Look at the waist and the wings. Minnesota says carpenter ants have narrow waists, elbowed antennae, and hind wings shorter than the front wings, while termites have broad waists and straight antennae. Colorado State adds that termite forewings and hindwings are equal in size. Inside the wood the difference is just as clear: Nebraska Extension says carpenter ant galleries are smooth, while termite damaged areas have mud packed into the hollowed out wood. Carpenter ants do not eat wood; Minnesota says they remove it to create galleries for nesting, which is why you find the frass piles outside the nest.

Free on-site estimate. Carpenter ants get a free estimate. We inspect inside and out, trace trails, check the moisture-prone spots, and locate the nests before quoting.

Treat the nest directly. Dust applied into wall voids and galleries, the method Kentucky describes as drilling small holes and applying dust into the suspected nest area. Non-repellent products on trails and entry points; Nebraska explains these are slow-acting and transferred from one carpenter ant to other members of the colony before causing death. Baits where the trails allow, so foragers feed the colony, per NC State.

Treat the parent colony outside where we find it, because Penn State says both nests have to go.

Written 6-month guarantee. If carpenter ant activity returns within 6 months, we come back at no charge. NC State's timeline is that bait based approaches may take 7 to 10 days before activity declines significantly, with complete elimination taking one to two weeks or longer for a large colony.

Fix the water. Kentucky's list is the right one: correct roof leaks, plumbing leaks, and other moisture problems that attract carpenter ants, clip back tree limbs and vegetation touching the roof or siding, and stack firewood away from the foundation and elevated off the ground. Minnesota adds removing tree and shrub stumps and roots. Penn State's general ant guidance is to keep vegetation and mulch at least 6 inches from the base of the house and to caulk cracks around windows, doors, and pipes. Damage is slow, per Minnesota, often taking years, so a house that fixes its leaks and keeps branches off the roof usually gets ahead of it.