Carpenter Bee

Carpenter bees are large, black and yellow bees often seen hovering around the eaves of a house, wooden fences, or the underside of a deck in late spring. They are most often mistaken for bumble bees, but differ in that they have a black shiny tail section.

The carpenter bee is so-called because of its habit of excavating tunnels in wood with its strong jaws. The round half-inch diameter entrance holes are usually found on the underside of a board. A tell-tale trace of coarse sawdust is often found on the surface beneath the hole. The holes start upward (or inward) about one-half inch or more, then turn horizontally with the wood grain and may run six to seven inches or more. Occasionally, several bees may use the same entrance hole and have individual branches off the main tunnel. If the same entrance hole is used for several years, tunnels may extend several feet in the wood. Wooden decks, overhangs and other exposed wood on houses are prime targets. Painted and treated woods are less preferred, but they are not immune to attack.

Unpainted or stained cedar, cypress and redwood shingles and siding are also attacked despite their pest-resistant reputations. Carpenter bees and carpenter ants, differ from termites in that they do not consume the wood as food, they simply excavate tunnels for nesting sites.  The holes they drill are perfectly round just like a carpenter would drill in wood.