The species of most importance are about 1-inch long and have a robust, bee-like shape.
Like bumblebees, carpenter bees are black with some yellow. One carpenter bee species in the southwest, the valley carpenter bee, has a metallic-black colored female and a tan colored male.
Carpenter bees chew out tunnels in wood in which to lay their eggs and provide a protected site for their larvae to develop. The female bee selects a suitable log or piece of wood and chews a round, 1/2-inch diameter tunnel into the wood. About one-inch deep, she turns at a right angle and chews a tunnel (nest gallery) about 12 inches in length. The bits of wood she chews off are deposited outside the nest and end up on the ground below. These bits of wood, called frass, often are streaked yellow from pollen on the female’s legs. An egg will be deposited at the end of the nest gallery; the female will then pack the gallery about an inch deep with pollen. This process is repeated until the entire gallery has been filled. The male carpenter bee guards the outside of the nest and tries to chase away potential predators. He does not have a stinger, but still causes concern with his aggressive buzzing if people venture near the nest site.
In nature, logs and dead trees and limbs are the targets for carpenter bees as nest sites. On homes, bare wood decks, fences, and window sills is usually attacked. Painted wood, however, is subject to attack although bare wood is preferred.
Painting bare wood that is being attacked by carpenter bees can deter some bees; however, it does not offer the best solution.