Are Carpenter Ants Dangerous to My House?

Short answer: They will not hurt you, but they can slowly damage your house. Carpenter ants dig tunnels in wood to nest, and they go for wood that has gotten damp. Find the moisture, find the nest, and you stop the damage.

Carpenter ants get blamed for a lot, so let's be clear about what they are. They are big, black or dark red ants, usually a quarter to half an inch long. They do not bite people much and they do not carry the usual kitchen-ant problems. The issue is what they do to wood.

They dig it, they do not eat it

This surprises people. A carpenter ant does not digest wood. It chews tunnels through it to make a nest, and it pushes the shavings out behind. Over months and years, a nest can hollow out a wall plate, a window frame, or a section of deck. One ant on the counter is not a crisis. A steady parade of big ants, especially at night, means a nest is nearby.

Why they pick your house

Dry, sound wood is a lot harder for them to work. They go for wood that has been softened by moisture. So the places to look are the ones with a slow leak or poor drainage:

• Window frames and door trim with failed caulk
• Under sinks and around dishwashers and tubs
• Roof edges where a leak has been going for a while
• Decks, porch posts, and fence boards touching the ground
• Old stumps, tree limbs touching the house, and wet firewood stacked against the wall

Signs you actually have a nest

The best clue is a small pile of coarse shavings that looks like sawdust mixed with bits of dead insect, sitting under a crack or a tiny hole in the wood. You might also see big ants walking the same line along a baseboard at night, or hear a faint rustling inside a wall when the house is quiet.

What helps, and what does not

Spraying the ants you can see will not do it, because the nest and most of the colony are tucked inside the wood. Real control means following the trail back to where they live, fixing whatever is keeping that wood damp, and treating the nest and the paths they use. Before anyone gets there, you can help: trim branches that touch the roof, keep firewood off the wall, and fix drips under sinks.

"Sensational service and attention to detail. Helped me get rid of a pesky insect problem that had been plaguing my place for months! Highly recommend, wish I had reached out sooner."

James L. ★★★★★

Seeing smaller ants in the kitchen instead? That is a different problem, and we cover it in how to get rid of tiny ants in your kitchen. For the big ones, our residential pest control starts with an inspection to find where they are coming from.

Seeing big black ants after dark?

We will track down where they are nesting and what is keeping that wood damp. Call or text us at (205) 855-7975.

Get a Free Estimate

Do carpenter ants eat wood?

No. They chew tunnels through wood to build nests and push the shavings out, but they do not digest it.

What do carpenter ants look like?

They are large ants, usually a quarter to half an inch long, and black or dark red. You will often see them moving at night.

Why are carpenter ants in my house?

They are usually drawn to wood that has gotten damp, from a slow leak, bad drainage, or failed caulk around a window or door.