How to Get Rid of Carpenter Ants Without an Exterminator

Catch one in a jar or on tape and look closely, because the treatment paths are completely different. Carpenter ants are large — 1/4 to 1/2 inch — black or red-and-black, with a pinched waist and elbowed antennae; their winged swarmers have front wings longer than the hind pair. Termites have no waist, straight antennae, and four equal wings, and they build mud tubes rather than pushing out sawdust. If what you find says termite, stop here and get a professional inspection — termite damage moves much faster.

Carpenter ants don't eat wood — they excavate smooth galleries in it to nest, and they overwhelmingly choose wood that's damp, rotted, or previously water-damaged. An indoor colony is almost always a satellite outpost of a larger parent colony outdoors in a stump, log pile, or dying tree, connected by scent-marked trails. So an indoor infestation is really two findings: there's a moisture problem in your structure, and there's a colony network that killing a few foragers won't touch.

Two hours after dark, set out tracking stations — a bottle cap of diluted honey or 25 percent sugar water, plus a dab of canned tuna — along baseboards, under sinks, and near where you've seen ants. Check them after one to two hours with a dim or red light: recruited workers will form a trail you can follow toward the nest. Listen along suspect walls with a glass or stethoscope for a dry, crinkling rustle, tap the wall and listen for a startled surge, and check every area with a moisture history: under bathrooms, around the dishwasher, behind gutters, at the chimney flashing.

Place commercial carpenter ant gel or liquid bait directly beside the active trails and tracking stations — never on the nest itself — in both sweet and protein versions, because colonies switch food cravings with the season and brood cycle. The bait's whole design is that workers survive long enough to carry it home, share it mouth-to-mouth, and dose the larvae and queen. That's also exactly why you must not spray: repellent insecticides kill the couriers before delivery and panic the colony into budding — splitting into multiple satellite nests somewhere new.

Gel and liquid baits lose their draw as they dry out, so replace them every two to three days, and swap between the sweet and protein formulas if interest fades — a colony ignoring sugar this week may mob protein instead. Don't scrub the floors near active bait placements yet; the ants' own scent trail is what funnels traffic to your poison. Expect heavy feeding for a few days, then a visible decline, with trails typically gone in one to three weeks.

If your tracking pinned the nest to a specific wall bay or kick-out hole, add a direct treatment: load a bulb duster with boric acid and puff a light, even film — not piles — into the hole or into 1/8-inch holes drilled just above the baseboard into the suspect stud bay. Returning workers pick the dust up on their bodies and groom it off inside the nest. A light film is the goal; ants detour around visible heaps of powder.

The colony chose your house because something is wet, and until that's fixed, the next colony will make the same choice. Chase down the usual suspects: clogged or leaking gutters, rotted soffit and fascia boards, roof and chimney flashing, weeping plumbing joints under sinks, and condensation in poorly vented crawl spaces and attics. Cut out and replace any wood that's soft enough to push a screwdriver into — carpenter ants can't establish in sound, dry lumber.

Carpenter ants commute along physical highways, so take them down: prune every branch and shrub until nothing touches the roof, siding, or deck; move firewood at least 20 feet from the house and up off the ground; and rake mulch back to leave a 6-inch gravel or bare-soil gap against the foundation. Then walk the exterior with caulk and seal the obvious entry points — cable and pipe penetrations, gaps where trim meets siding, and openings around the foundation sill.