Carpenter bees bore into wood to nest, but it is possible to prevent them from boring into the wood on your house with a few simple tips. Carpenter bees prefer to nest in soft wood that is unprotected from the sunlight. They resemble bumblebees, but are not as hairy, and bore a 1/2 inch hole into wood and tunnel to create a nest. These bees are likely to return each year to the same nest, boring further into the wood and making their nest larger. This can damage the wood significantly if it is not prevented.
Spray an insecticide on and around the holes created by the Carpenter bees.
Fill in any holes created by the Carpenter bees. Use exterior caulk or a wood plug to fill the holes created by the bees. This will help prevent the bees from returning to the same nest and creating more damage.
Paint over the area with exterior grade paint. Likewise, paint any unfinished wood that the bees will have access to. Carpenter bees are much more likely to bore into unfinished wood so adding any finish, even wood stain, will help prevent the bees from damaging the wood.