Carpenter Bees: Best Way to Get Rid of Them

Money Pit Team asks,

Every spring, carpenter bees show up around our house. They seem to be living under the eaves of our garage. They leave ugly brown trails at the entrances of their “homes”.

We have tried “over the counter” pest sprays which works for a while. Our neighbors have also suggested leaving a 2-liter bottle of soda open, with a little soda in the bottom, and letting the bees fly in. They apparently are unable to fly out.

What is the best way to get rid of them? Are they as bad as termites? It might help you to know that our homes are fairly close to each other and the bees occupy houses on either side of me as well. Which makes it hard to get rid of them completely!

Our Answer

Carpenter bees are really fascinating bees in that they are solitary and don’t have a colony. Females will bore into wood (they seem to prefer soft wood and cedar) and even will bore into pressure treated lumber on decks. The bees will then turn at 90 degrees in their boring and lay an egg, put in pollen, wall it off, lay an egg, put in food, wall it off etc. Bees that hatch out can reinfest and one “daughter” can take over the original gallery.

Since these bees don’t eat wood, any preservative such as pressure treated lumber preservative will not affect them. Over the counter products if sprayed usually won’t work in that you must penetrate the galleries. Painting the wood sometimes will discourage the bees but is not a cure for an active infestation. Treating the galleries preferably with an insecticidal dust will be necessary and in extreme cases, removing the damaged wood might be required. Dusts are not readily available to the homeowner.

Some people seal the holes with epoxy or durable hard setting material but many times the holes are not easily accessible (nature’s way of preserving the bees). The good news is that these bees, while large, are not aggressive but the female can sting if threatened. Hint: expect to see carpenter bee activity now in the south and progressing north in the next few weeks. The soda bottle method might work for sugar loving yellow jackets but probably isn’t going to work for carpenter bees which prefer pollen over sugars.