While the damage to wood from the drilling activities of a single bee is slight, the subsequent year’s broods will expand the tunnel through branching activities and may cause considerable structural damage. Additionally, they will commonly defecate on the wall or other item directly below the opening causing stains.
Carpenter Bees are somewhat attracted to your flowers and the woodwork on the outside of your house. Sofit, siding, molding eves and wood trim. Your flowers seem to be a great source of food and your home will become their home when they drill into it and leave their babies in the tunnels to grow up and eat your house some more.
Female carpenter bees make nests by tunneling into wood. They make an initial upward hole in an overhang, eaves trough, or similar structure. Then, they make one or more horizontal tunnels. The final nest usually resembles a T. Unlike termites, carpenter bees (also called woodcutters) do not eat wood. They discard the bits of wood, or use them to make partitions (walls) inside the tunnels of their nests. The tunnel functions as a nursery for brood and the pollen/nectar upon which the brood subsists.
Males will visit flowers only to feed themselves, spending the rest of the time hovering in their territory and investigating any movement, or guarding flowers where they might encounter females . Females spend the majority of their time gathering nectar and pollen to provision their nests.