Carpenter Ants in Rockford Homes: Signs and Causes

What they look like

Carpenter ants are large, often black or black and red. Seeing large ants indoors in late winter or early spring, before it's warm outside, suggests a nest inside the house.

Frass

Carpenter ants don't eat wood; they excavate it to nest and push out fine, sawdust-like material called frass, often mixed with insect parts. Small piles below windows, door frames or baseboards are a key sign.

Where they nest

Damp or softened wood is their favorite: window sills, door frames, roof edges, decks, porches and wood near plumbing leaks. They may also nest in dead trees or stumps outside and forage indoors.

Fix the moisture

Repairing leaks, improving gutters and replacing rotted wood are part of the solution. Without that, ants return.

Treatment

Professionals locate nests and use targeted treatments in wall voids, baits and exterior treatments. Results usually build over days.

Prevention

Trim branches away from the roof, keep firewood off the ground and away from the house, and fix leaks quickly. See ant control.

Outdoor colonies

Many carpenter ant problems start in a dead tree, a stump or a pile of old lumber near the house, with a satellite nest inside the walls. Removing rotting wood from the yard and keeping branches from touching the roof cut off the easiest routes in.

When it's more than ants

If you find frass or soft wood, the moisture that attracted the ants may also be damaging the structure. Have the source of the moisture checked by the right tradesperson, whether that's a roofer, plumber or carpenter.

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• Checking an Illinois Pest Control License