Carpenter ants or termites? How to tell from the damage
The short answer
Carpenter ants excavate wood to nest in it and push the shavings out, so you find coarse sawdust-like frass below a clean, smooth gallery. Termites eat the wood and line their galleries with mud, so the tunnels look dirty and packed rather than sanded.
What you can see without opening anything up
- Frass. Carpenter ants dump excavated material, so a small pile of what looks like pencil shavings with insect parts mixed in is a strong sign. Termites do not produce this.
- Gallery surface. A carpenter ant gallery is smooth and clean, almost sanded. A subterranean termite gallery carries soil and looks packed with mud.
- Mud tubes. Pencil-width earth tubes running up a foundation wall, a pier or a joist are termites, and they are one of the few signs that is essentially unambiguous.
- Sound. Tapping affected timber gives a hollow note either way, so this tells you there is damage, not which insect caused it.
Why the answer changes the job
Carpenter ants are a colony you locate and treat, often with a parent nest outdoors in a stump or a wet section of timber and a satellite nest in the building. Subterranean termites are treated as a soil-and-structure problem, usually with a continuous treated zone or a monitored bait system. Buying one treatment for the other wastes the money and leaves the actual problem running.
Both are also telling you something about moisture. Carpenter ants prefer wood that has been damp; termites need moisture contact. A competent inspection looks for the leak, the grade problem or the ventilation fault behind the infestation, not only for the insects.
Also asked
- Do carpenter ants eat wood?
- No. They tunnel through it to make galleries and discard the material. That is why the debris below the nest is one of the clearest ways to tell them from termites, which consume what they tunnel through.
Companies whose reviewers name termites
3,152 pest control businesses in the United States and Canada have reviewers who write about termites. Every listing shows the full rating distribution rather than the average, the share that is one or two star, and whether the owner replies.
Read next
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General information about pest problems and about hiring, not advice about your specific property. Pest control licensing, wildlife protection and landlord and tenant law are all set state by state and province by province across the United States and Canada, so your own regulator is the current answer. How we read the data.