Bee-gone! Effective Ways to Keep Carpenter Bees From Buzzing Around Your Home

The thing that keeps carpenter bees away is a solid coat of paint. They bore into bare, weathered softwood, and university extension entomologists agree that well-maintained painted wood is rarely attacked. If bees are already nesting, the fix has three steps: dust an insecticide labeled for bees into each hole, wait a day or more, then plug the hole and paint over it. Sprays, smells and decoys are a distant second.

Here’s how to spot them, what actually works, and what’s mostly folklore.

01Is it a carpenter bee?

Carpenter bees look like bumblebees, but the abdomen gives them away. A carpenter bee’s abdomen is shiny black and hairless. A bumblebee’s is fuzzy with yellow and black bands. Carpenter bees are 1/2 to 1 inch long, and in spring you’ll see them hovering near eaves, deck rails and fascia boards.

Look for this when you walk the outside of the house:

• Perfectly round holes about 1/2 inch across, usually on the underside of a board where rain doesn’t hit them.
• Sawdust-like shavings piled on the ground or deck below the hole. The bees don’t eat wood; they push the chewed bits out.
• Yellowish-brown stains streaking down from the hole. That’s bee droppings.
• A bee hovering in your face. That’s usually a male guarding his patch. Males can’t sting. Females can, but they rarely do unless you grab one.

02How much damage they really do

One season of one bee does little harm. The hole goes in about an inch, then turns and runs along the grain, where the female builds a row of cells for her eggs. A new gallery is usually 4 to 6 inches long.

The trouble is that they come back. New females would rather extend an old tunnel than start a fresh one, so the same board gets mined year after year. Alabama Extension reports galleries up to 2 feet long with repeated use, and other extension sheets describe much longer ones. Over several years, a fascia board or deck rail can get hollowed out enough to need replacing.

Woodpeckers make it worse. They go after the larvae inside and tear the wood open to get at them, turning a neat 1/2-inch hole into a ragged gouge. Open holes also let water into wood that was dry before, and that can lead to rot. If you’re inspecting a house you’re buying, chewed-up fascia with woodpecker damage is a sign the bees have been there for years.

03What they go after

Carpenter bees want bare, weathered softwood: cedar, redwood, cypress and pine are the usual targets. Common spots:

• Fascia boards and the underside of eaves
• Deck rails, porch ceilings and pergolas
• Wood siding and window trim
• Fences, sheds and outdoor furniture

They also like wood thicker than about 2 inches, so a 2x6 rail or a 4x4 post is more appealing than thin trim.

04Prevention: paint is the answer

Paint the wood. Clemson’s Home & Garden Information Center calls an oil-based or polyurethane painted surface the most effective deterrent. Penn State Extension says to paint or varnish the entire surface, not just the spots with holes.

Stain is the weak spot. Penn State notes that stained wood “is not usually protected,” and NC State says stains and preservatives are less reliable than paint, though they may give a little protection compared with bare wood. A cedar deck or fence with a semi-transparent stain will still attract bees, especially once the stain weathers.

A few more prevention options:

• Keep up with the finish. Bees go for weathered wood. Re-coat when the paint starts peeling or the wood turns gray.
• Use non-wood materials where it makes sense. University of Maryland Extension notes that vinyl or aluminum siding keeps carpenter bees out entirely. Aluminum or vinyl fascia wrap is a common fix on eaves that get hit every year.
• Pressure-treated lumber is less attractive than raw cedar or pine. Alabama Extension lists it among the deterrents.

For more on picking and finishing wood that bees leave alone, see our guide on protecting wood from carpenter bees.

05Getting rid of bees that are already nesting

If you plug a hole while bees are still inside, they’ll often chew right back out through the caulk. The order matters: treat first, wait, then seal.

1. Pick the right time

Early spring, before the females finish their tunnels and lay eggs, is the best time. Late summer is the second-best window. That’s after the new adults come out (around August) and before they settle in for winter. Treat in the evening or at night, when the females are inside. If you need a light, Penn State suggests covering the flashlight with red cellophane so it doesn’t stir the bees up.

2. Dust the holes

Use an insecticide dust labeled for bees or wasps and puff it straight into each entrance with a bulb duster. Extension sheets say dusts usually work best inside galleries because they last longer than sprays. NC State lists bifenthrin, cyfluthrin, deltamethrin and lambda-cyhalothrin as active ingredients that work. Some people use boric acid dust instead; if you do, check that the product label lists carpenter bees.

Use a light hand. University of Maryland Extension notes that heavy doses can repel the bees before they pick up a lethal amount, so the goal is a light coating inside the entrance. Wear gloves, goggles and a dust mask, and follow the label; it’s the law, not a suggestion.

Bees still flying in daylight can be knocked down with a wasp-and-hornet aerosol aimed into the hole.

3. Wait, then plug

Leave the holes open so returning bees walk through the dust. Clemson says to wait at least 24 hours; other sources say several days, until you stop seeing activity. Then seal each hole:

• A short piece of wooden dowel coated in wood glue, tapped in flush, or
• Wood putty or exterior caulk.

Then paint over the patch. An open, unpainted hole is an invitation to next year’s bees.

4. Plan to repeat

Surface sprays wear off fast. Clemson says pyrethroid sprays on wood last less than 30 days. Penn State suggests checking and treating in spring, midsummer and early fall. Expect to find a few new holes the next spring if nearby wood is still bare.

06Traps

Carpenter bee traps are small wooden boxes with 1/2-inch holes drilled into the sides at an upward angle and a clear bottle or jar hanging below. Bees crawl in looking for a tunnel, head toward the light, and drop into the bottle. Clemson and Kentucky’s entomology department both describe them. Traps catch bees, but they reduce numbers more than they protect a specific board. Hang them near the problem area in early spring and use them alongside paint and plugging, not instead of them.

07Sprays, scents and decoys: what to expect

You’ll see plenty of advice to spray citrus oil, almond oil, vinegar or eucalyptus on wood, plant mint, or hang a paper bag as a fake nest. None of these is backed by solid research on carpenter bees, and none of the extension fact sheets above recommends them as a main control. At best, a scented spray wears off with the first rain and has to be reapplied constantly. A decoy might make a bee choose a different spot, but it won’t move bees out of a nest they’ve already dug.

They’re cheap and harmless to try on a shed or a fence you don’t care much about. On fascia or a deck, don’t count on them.

08When to call a pro

Call a pest control company if:

• Holes are high on the eaves and you’d need a tall ladder to reach them.
• You’ve found dozens of holes, or new ones keep appearing after you’ve treated.
• Woodpeckers have torn into the wood, or a board feels soft or spongy when you press a screwdriver into it.
• You’re allergic to stings or don’t want to handle insecticides.

A pro will dust the galleries the same way you would, just with better reach and gear. If the wood is hollowed out or rotten, the real fix is a carpenter: replace the board, then paint or wrap it.

09A note on leaving them be

Carpenter bees are pollinators, and the males are all bluster. If the bees are drilling into an old stump, a woodpile or a fence post at the back of the lot, you can leave them alone. Save treatment for wood you care about.

10Your spring checklist

1. In March or April, walk the house and check the underside of eaves, deck rails and trim for 1/2-inch holes, sawdust and stains.
2. Dust active holes in the evening with a product labeled for bees.
3. Wait at least a day, then plug each hole with a glued dowel or putty.
4. Paint the repaired wood, and any other bare or gray softwood nearby.
5. Check again in late summer and fill any new holes before winter.

Related: Inspect Your Roof From the Ground: What Binoculars and the Attic Tell You · Window Wells and Basement Egress: Covers, Drains and a Way Out