Carpenter bee holes appear about 1/2 inch in diameter and most often occur in areas protected from the weather. The holes they bore compromise wood's structural integrity, cause stains and attract woodpeckers. Check for entrance holes on common nesting areas such as structural timbers, eaves, window trim, fascia boards, siding, wooden shakes, decks and outdoor furniture. There will often be coarse sawdust on surfaces below the hole as carpenter bees do not actually ingest or feed on the wood itself. You may also observe woodpecker damage to the structure as these birds will attempt to reach larvae in the galleries. Another sign of an active infestation is the burrowing sound from the female carpenter bee which sounds like a vibration within the wooden surface.