How To Keep Carpenter Bees Away From Your Home

Gardeners know pollinators are essential, especially those industrious bees buzzing tirelessly in and out of squash blossoms and trumpet vines. But one kind of bee may wear your patience thin if you’ve discovered their handiwork: Carpenter bees! If you’ve found perfectly round half-diameter holes drilled into your deck timbers, wood siding, mailbox posts, or outdoor furniture with a little sawdust beneath the holes, you may be housing these gentle bees.

Carpenter bees (Xylocopa virginica) actually are fascinating native pollinators. They’re about three-fourths to one-inch long with shiny abdomens, not fuzzy back ends like bumble bees. They may look intimidating, but they’re docile bees who are more interested in going about their own bee business than in bothering you. “Carpenter bees are solitary. She’s a single mom who builds a nest and forages for her young,” says Keith Delaplane, PhD, professor of entomology at the University of Georgia. “She’s just trying to make a new generation.”

Ahead, here’s what else you should know about carpenter bees, as well as how to discourage them from nesting in and around your house if you don’t want to deal with their holes:

Are Carpenter Bees Dangerous?

Social insects such as honeybees and some types of wasps live in huge colonies and will aggressively drive you off by stinging if you accidentally disturb their nests. (Read about how to keep bees away from your house and how to keep wasps away from your home). But a solitary carpenter bee just wants to build a home for her family.

The bees emerge in the spring. “The females are discreet, sneaking in and out of their holes. But the males are territorial. You’ll see them hovering around, battling and chasing each other,” says Delaplane. They’ll divebomb you, too, if you get close.

But carpenter bees are no threat to people or pets. Males have no stingers; they’re just interested in fighting each other and finding a female. And while females do have stingers, you’d have to grab and squeeze her hard. “In my more than 30 years in entomology, I’ve never heard of a single sting from a carpenter bee,” says Delaplane. 

Carpenter bees actually are important pollinators. In fact, it’s been discovered that they contribute to blueberry pollination by stimulating the presence of honeybees. “Carpenter bees steal nectar from the side of blueberry flowers instead of pollinating the flowers. Honey bees are attracted to the holes, arriving in huge numbers to pollinate the berries,” says Delaplane. It’s an amazing example of how insects work “together” to get a job done.

Why Do Carpenter Bees Drill Holes in My House?

The simple answer is they need a place to call home. After the female mates, she excavates a hole into a wood surface with her strong mandibles. She drills in about a half-inch, then makes a turn and tunnels with the grain. Each tunnel may take up to a month’s worth of work. She creates a series of cells where she’ll deposit food and lay her eggs. The next generation emerges in late summer and overwinters in the old tunnels.

The good news is that carpenter bees don’t present a huge risk to your home. “They don’t do structural damage, like termites can,” says Delaplane. “Most of the damage is cosmetic, and occasionally, if a tunnel has been used by multiple generations, it will breach the surface of the wood.” Rarely, a secondary problem may occur if woodpeckers discover the bounty and drill into the wood in search of bee larvae.

How Do I Stop Carpenter Bees from Drilling?

Let’s say you’ve had enough of their antics. It’s not easy to stop them because this is what they do! For most people, an occasional hole isn’t a big problem. However, if your patience has been exhausted, you can try a few options:

·  Add a protective coat to wood surfaces. Carpenter bees are diverted from painted, sealed and pressure-treated wood surfaces. It’s not foolproof, but it may reduce the numbers, says Delaplane.

·  Use vinyl, aluminum, or cement board siding and composite products when possible because they can’t penetrate these materials.

·  Protect the rough ends of timbers with wire screening or metal flashing.

Unfortunately, applying insecticides or essential oils to surfaces isn’t useful. There’s little evidence these products work, and the substances don’t penetrate the wood. Products also would have to be reapplied frequently, and treating every potential surface in your yard would be impossible. As for traps, they’re worthless. “You might get some visceral satisfaction from trapping one, but it’s not going to solve your problem,” says Delaplane.

Should I Seal Carpenter Bee Holes?

This is one effective way to discourage repeat nesting. For tunnels within easy reach, treat entrance holes. Spray the tunnel opening with a product labeled for carpenter bees. Leave the holes open for a few days, then plug them with caulking, wood putty, or a wooden dowel and wood glue. If you don’t treat the hole, the bees can chew their way out. Sealing the holes also helps prevent moisture intrusion and wood decay.

But if you have a large-scale problem, such as multiple carpenter bees drilling into your home’s wood siding, woodpeckers in search of an easy meal, or holes located high above ground level requiring the use of a ladder, consult a professional pest control company. The company should treat individual holes to ensure there are no return visitors, says Delaplane.