Reviewed by William "Willy" Vizcarrondo, NYS DEC Certified Commercial Pesticide Applicator C1825832. Updated September 23, 2026.
Short answer
It kills the ants you spray and nothing else. University of Minnesota's extension says spraying foraging workers is not effective because most ants forage outside and do not come in contact with the insecticide, and the nest keeps producing. Getting rid of carpenter ants means treating the nest in the house and the parent colony outside, not the trail on the counter.
Because the trail is the smallest part of the colony. Penn State notes a carpenter ant colony has grown to about 2,000 to 3,000 workers by the time it produces swarmers, with a parent colony usually within 100 yards of the house and satellite nests inside. The dozen ants on the kitchen counter at 11 p.m. are foragers, and Minnesota's extension notes most of the colony's foraging happens outside where a spray indoors never reaches. Spray the counter and the queens keep laying, the satellite nest in the bathroom wall keeps growing, and next week's foragers take a different route around the residue. Penn State's summary of the homeowner experience is that efforts frequently fail and professional materials are often required. Repellent sprays can make it worse by scattering foragers into new voids.
Bait the foragers, treat the nest, fix the water. UC IPM's guidance is that baits should be slow-acting formulations so the ants carry the product back to the nest and share it; Minnesota's extension notes baits can take weeks or months to achieve control and warns never to apply insecticides near baits, because a spray next to a bait kills the ants before they can carry it home. The direct route is finding the nest, which means tracking ants at night and listening for rustling in the wall, then treating the void; Minnesota's extension describes professionals drilling small holes, about 1/8 inch, and applying insecticidal dust into the nest area. Then the parent colony outside gets found and treated, because Penn State notes workers travel between the satellite and parent colonies and both must be destroyed. Last, the moisture: Penn State notes carpenter ants won't infest sound wood under 15 percent moisture, so the leak or the overflowing gutter that made the wood soft gets fixed and the damaged wood gets replaced.
Weeks to see the trail stop, longer to be sure. A dusted nest goes quiet within days. Baited foragers keep carrying product for a week or two before the colony collapses, and the parent colony outside may take a return visit to locate. Minnesota's extension is honest about the timeline for baits, weeks or months, and a satellite nest that survives will send a new trail to the same water source next spring. That's why the follow-up matters as much as the first visit.
The carpenter ant call in May is almost always a homeowner who sprayed in April. In the wooded North Shore towns, Dix Hills, Huntington, Smithtown, the parent colony is in an oak stump or a dead limb near the house and the satellite is in the roofline; on the South Shore it's more often a deck ledger or a bathroom wall. Bobby Bugs treats the nest inside, baits the foraging routes, tracks down the parent colony in the yard and points out the leak that started it. Carpenter ant treatment on Long Island carries a 6-month written guarantee and a free estimate.
Related
Sometimes, slowly. A slow-acting bait the ants actually take can reach the nest, but Minnesota's extension notes control can take weeks or months, ants often ignore a bait when better food is around, and any spray nearby ruins it. Baits also don't fix the wet wood the colony is living in.
Because that's when they forage. UC IPM notes carpenter ants are most active after sunset, and Minnesota's extension puts peak foraging between sunset and midnight. A trail at night with none in the day is normal, and it's also the best time to follow them back toward the nest.
Not from the same colony if the nest, the parent colony and the moisture were all addressed. New colonies can move in later from the yard if the wet wood stays wet, which is why replacing damaged wood and fixing the leak are part of the job. Our carpenter ant guarantee covers 6 months.
Still not sure? Call (516) 509-6001 and we'll tell you what you're dealing with.