The answer to 'when to treat for carpenter ant' is that carpenter ants should be treated as soon as an infestation is detected. Carpenter ants are wood-destroying insects that can cause significant damage to the structural integrity of a home if left untreated. They typically become active in the spring and early summer months, so it's important to inspect for signs of an infestation and take action quickly.
Carpenter ants prefer damp, decaying wood and will establish nests both inside and outside the home. Signs of a carpenter ant infestation include seeing the ants themselves, finding piles of wood shavings or debris, and hearing rustling or clicking sounds within the walls. If you suspect a carpenter ant problem, it's best to contact a professional pest control technician to properly identify the issue and develop a treatment plan.