Carpenter bees, which burrow into wood, are often confused with bumble bees because of their appearance. To tell the difference, look at the abdomen: If it is mostly black, then it is a carpenter bee. Carpenter bees can be a nuisance and can ruin the wood on your home. The best way to tell if you have carpenter bees is if you notice 1/2-inch holes in unfinished wood with telltale piles of sawdust under the wood. You might also notice the bees' fecal matter: yellow streaks that stain the wood just below the burrowed hole. The male bees guard the holes while the females nest inside the wood. It is not enough to only get rid of the existing carpenter bees because the larvae will eventually hatch and you will have an infestation once again.
Things You'll Need
Varnish, stain or paint
Liquid residual insecticide
Knockdown insect aerosol spray
Finish the wood that the bees are burrowing in. Carpenter bees tend to return to the same nesting sites, and they are most attracted to unfinished wood. Finishing the wood with a stain or paint and filling in any cracks and holes with wood putty will make the wood less attractive to the bees.
Apply a liquid residual insecticide to the wood according to manufacturer instructions.
Apply a knockdown insect aerosol spray to the nesting holes. This will kill the female bee and the males when they return. Apply a dust insecticide with a duster all around the wood and especially in the holes. Wait three months to seal off the nesting hole until you are sure the larvae have not hatched. Otherwise the newly hatched bees will just bore new holes to get out.
Apply a liquid residual to the infested surfaces. Wait three or four months, and then seal off the entrances to the nests with wood putty or steel wool.