Carpenter ants bore into wood and leave behind wood fragments similar to sawdust. This is a good indication of carpenter ant activity. Infested wood will also sound hollow when tapped with a solid object. Carpenter ants are most effectively treated when the nest is found and infested wood can be removed.
Sealing outdoor cracks and crevices around doors and windows with a waterproof silicone caulking will help reduce carpenter ant infestations. Also, spraying outdoor areas with an insecticide labeled for this use can help reduce carpenter ant incidence.