Eliminate excess moisture and wet wood to make the environment less hospitable to ants. Fix leaks in the roof, pipes, and sinks. Insulate sweating pipes. Use vapor barriers when insulating outside walls. Replace water-damaged wood.
Carpenter ants seek water-damaged wood because it is easier to excavate than sound wood.
Furthermore, immature ants require high humidity for development. Place a Bait. Purchase a containerized or liquid insecticide bait after you have tried non-chemical methods. Be sure to keep your house free from any sweets or grease that might distract the ants. The first sign that the bait is working is an increase in the number of ants.