The excavating bee will bore directly into the wood with her mouthparts for about 1 inch, then turn sharply and bore at a 90 angle usually along the grain of the wood. Normally, the gallery will extend about 4 to 6 inches, but with repeated use galleries have measured 10 feet long. Nest sites made by a single bee result in slight damage. Repeated colonization over several years, however, may result in considerable damage. Insecticide additive paints are available which may repel bees attempting to nest.
Wood stains provide little repelling action.
Nail holes or exposed saw cuts should be filled in with wood putty or dowels and painted. If practical, remove severely damaged wood and replace with chemical pressure-treated wood to deter nest construction. To further discourage carpenter bees looking for potential nesting sites, a homeowner should secure all doors, windows and other building openings during the spring. Non-wood surfaces such as vinyl siding are not damaged by carpenter bees. Established bee galleries should be sprayed with liquid insecticides or dusts labeled for wasp or bee control.