They overwinter as juvenile adults in the tunnels from the previous year. They often refurbish old tunnels in preference to boring new ones. The tunnel may be a foot or more in length. The eggs are placed in cells in a tunnel constructed by the bee. The larvae hatch and feed on the pollen and nectar and then pass through the pupal stage.
New adults emerge before cold weather sets in during the early fall.
The female carpenter bee, like many other bees, can sting but it is uncommon for her to do so, and the males do not sting. When tunnels are found, treatment with an insecticide and sealing of the tunnel is recommended. Wasp, hornet and bee aerosol sprays are effective and easy to use. A few days after application, if no activity is observed, the holes should be plugged deeply with putty or caulking compound. If the tunnels are plugged without first killing the insects, carpenter bees trapped inside will bore new openings.