Final answer:
The best treatment for a carpenter ant entrance hole is exterior baiting around the perimeter of the structure. Bait stations or traps containing ant bait are placed near the entrance holes and along the ant trails. The ants carry the bait back to their nest, effectively controlling the entire colony.
Step-by-step explanation:
The best treatment for a carpenter ant entrance hole is Exterior baiting around the perimeter of the structure. This involves placing bait stations or traps containing ant bait near the entrance holes and along the ant trails. The bait contains slow-acting insecticides or attractive food materials that the ants carry back to their nest, effectively controlling the entire colony.