The sexually mature bees do not mate in the fal1 but prepare for overwintering by gathering pollen. Usually little or no nest construction occurs in the fall. Carpenter bees are active in the spring with the female hovering in front of the nest entrance awaiting the male for mating. Males at this time are very aggressive and menacing when disturbed but fortunately cannot sting. Female carpenter bees will sting only if molested.
Carpenter bees prefer softwoods such as redwood, cypress, cedar, and pine tor nesting sites.
Hardwoods occasionally are used, but only after they have been softened by exposure or decay. Damage to structures is usually slight and amounts to only cosmetic defacement. When subsequent generations expand old galleries, or construct new ones in the same picce of wood, serious damage may result. Abandoned nests of carpenter bees may be inhabited by wasps, ants, other bees and scavengers such as dermestid and darkling beetles. They can be controlled by eliminating the plant or by careful pruning.