Do carpenter ants eat the wood in my house?
No. Carpenter ants excavate wood to build galleries but do not eat it. They feed on sweet liquids and other insects. The damage comes from tunneling, which can weaken beams, sills and porch framing over time, especially where the wood is already wet.
The galleries are smooth, almost sanded, unlike the muddy tunnels of termites. The frass that falls out of them is a mix of wood shavings and insect parts.
A small colony does little harm. The risk grows with time and with the amount of damp timber available, which is why locating the moisture is as important as treating the ants.
Why do carpenter ants show up in spring?
They emerge as winter ends and the weather warms, and wet wood from snowmelt and ice dams supports nesting. A wasted, hungry colony forages hard in spring. Winged ants emerging indoors in spring can mean an established nest inside the house.
For months the ants are mostly inactive. As the temperature rises, foragers go out looking for food, and you notice them in the kitchen.
A single ant is not a sign of an infestation. A steady procession, or winged ants in a room, is.
What causes the wet wood they like?
Roof leaks, ice dams, failed flashing, clogged gutters, leaky pipes and porch decks that stay wet are the usual causes. In a snowy region the thaw puts a heavy load of water against the roof and walls, and old caulk or paint may not hold.
Window sills and the wood beneath them are frequent spots, as are the ends of porch beams and the bottom of door frames.
Fixing the leak does two things. It makes the existing nest less comfortable, and it removes the reason a new colony would settle in.
- Ice dams that push meltwater under shingles
- Gutters that spill onto siding or a sill
- Porch posts and decks that sit in contact with soil
- Plumbing leaks inside walls
- Tree limbs that rub against the roofline
Can I treat carpenter ants myself?
Sprays on visible ants rarely reach the nest and can scatter the colony into new parts of the house. A technician finds the nest first, which is the step most do-it-yourself efforts miss. Baits from a store may help with foragers, but not the colony.
Killing the ants you see is like pulling weeds by their tops. The colony keeps sending more.
If you have already sprayed, tell the technician which product you used and where. It changes how baits are placed.
What does a spring inspection for carpenter ants involve?
A technician checks the places that hold moisture: window sills, porch framing, roof edges, the base of door frames and the attic, using a probe, a flashlight and sometimes a moisture meter. The aim is to find soft wood and the ant route to it before damage spreads.
Inspection is as much about the building as the ants. The technician reads the history of leaks from stains and paint, and asks where you have seen the ants and when.
Expect to be asked about trees and stumps near the house, firewood storage and any recent repairs or additions. Each can point to the source of the colony.
