Q: Last year and again this year, we have seen carpenter ants in our unfinished basement. An inspection found no termites. Last year we had the exterior painted and caulked, and we replaced rotted wood. We also placed baits for common ants in the basement, where we had seen ants and insect excrement. The visible ants then disappeared, but this spring, we see more excrement and ants. We’ve read that carpenter ants build nests in walls and other wood. How do we know if there are nests? Should we open walls or get a pest-control service? Are DIY powders and sprays effective?
