How to Get Rid of Carpenter Bees
Quick answer: Treat carpenter bees by puffing insecticidal dust directly into each active hole in spring or early summer, when the bees are boring. Wait several days so bees carry the dust deeper, then plug the holes with wood filler or a dowel. Finally paint or seal the bare wood so new bees cannot start fresh tunnels.
Carpenter bees look alarming, hovering around your porch and dive-bombing anyone who walks by, but the real problem is out of sight. Females bore into bare wood to lay eggs, and year after year they reuse and extend the same tunnels, called galleries, until a fascia board, deck rail, or eave is riddled from the inside. The bees rarely sting, yet the slow structural damage and the woodpeckers that tear into siding to eat the larvae make them worth dealing with promptly.
This guide covers how to tell a carpenter bee from a harmless bumblebee, the damage they actually do, the right way to treat and seal the galleries, the timing that makes treatment work, and the point where the smart move is to bring in a licensed pest control pro.
Identify carpenter bees first
Carpenter bees are large, about an inch long, and are frequently mistaken for bumblebees. The fastest way to tell them apart is the abdomen: a carpenter bee has a shiny, hairless, solid-black upper abdomen, while a bumblebee's abdomen is fuzzy and marked with yellow. The other giveaway is behavior and evidence. Carpenter bees are solitary, hover around wood, and leave a perfectly round hole about half an inch across, often with a fan of coarse sawdust below it and yellowish staining beneath the entrance.
| Trait | Carpenter bee | Bumblebee |
|---|---|---|
| Abdomen | Shiny, bare, solid black | Fuzzy with yellow bands |
| Nesting | Bores round holes in bare wood | Nests in ground or cavities, does not drill wood |
| Social | Solitary, one female per gallery | Social colony with many workers |
| Behavior near people | Males hover and dart but cannot sting | Foragers ignore people, sting if provoked |
| Evidence left behind | Round holes, sawdust, yellow staining | No wood damage |
The bees hovering aggressively in your face are almost always males, which are territorial but stingerless. The females can sting but are docile and rarely do unless handled. The flying display is mostly bluff; the quiet drilling is the part that matters.
The damage carpenter bees actually do
A single hole looks trivial, and one season of one bee is not a structural threat. The problem is cumulative. Each round entrance turns a right angle and runs several inches along the grain, and females extend existing galleries and add new branches every year. Over multiple seasons a favored board can hold many interconnected tunnels that weaken it from within.
Carpenter bees most often target:
- Unpainted or weathered softwood: eaves, fascia, and soffits.
- Deck railings, joists, stair rails, and the underside of deck boards.
- Wooden siding, trim, window frames, and door frames.
- Fence posts, pergolas, playsets, and outdoor furniture.
- Exposed rafters and ridge beams in barns, sheds, and porches.
Woodpeckers are the hidden multiplier. They hear or smell the larvae inside the galleries and tear open the wood to eat them, turning a few clean half-inch holes into ragged, gaping damage. Treating the bees early removes the food source that draws woodpeckers in the first place.
Galleries also let moisture seep into the wood, which invites rot. That combination of tunneling, woodpecker excavation, and water intrusion is what turns a cosmetic nuisance into a repair bill.
When you can treat carpenter bees yourself
Do-it-yourself treatment is reasonable when the affected wood is reachable from the ground or a short, stable step stool, the holes are few and easy to see, and you are comfortable working near hovering bees at dusk. Because the males cannot sting and the females are reluctant to, carpenter bees are generally safer to treat yourself than wasps or hornets.
Step back and call a pro when galleries are extensive across many boards, when the wood is high on a second story or roofline that needs a ladder, when woodpeckers have already opened the wood, or when anyone in the household has a bee-sting allergy and would rather not chance it.
Step-by-step carpenter bee treatment
1. Find and mark the active holes
In daylight, watch the wood for bees entering and exiting, and look for fresh sawdust and yellow staining, which mark active galleries. An open hole with no activity may still hold a female or developing larvae, so treat every hole you find rather than only the busy ones. Marking each entrance with a pencil or a bit of tape makes them easy to locate again after dark.
2. Treat at dusk and dust the galleries
Treat in the evening when the bees are inside and calm. Puff an insecticidal dust labeled for carpenter bees directly into each hole using a hand duster with a narrow tip, so the powder coats the tunnel walls. Dust works better than a liquid spray here because bees walking through the gallery pick it up and carry it deeper, reaching larvae you cannot reach directly. Wear long sleeves, gloves, and eye protection, and stand to the side of the hole rather than directly beneath it.
3. Wait several days before you plug
Leave every hole open for several days after dusting. This is the step people get wrong. If you seal a hole immediately, you trap live bees that will simply chew a new exit through the wood, and you stop foraging bees from tracking the dust deeper into the nest. Give the treatment time to spread and the adults time to die before you close anything.
Never plug a carpenter bee hole right after treating, and never plug an untreated hole. Trapped bees chew fresh tunnels to escape, and a sealed but untreated gallery can still hold larvae that emerge the next season. Treat first, wait, then plug.
4. Plug the holes once activity stops
After several days with no activity, fill each hole to keep out water and discourage reuse. Push a wooden dowel dipped in wood glue into the tunnel, cut it flush, or pack the opening with wood filler, steel wool, or caulk. Sealed galleries are far less attractive to next year's bees, which prefer to reopen an existing tunnel over drilling a new one.
5. Paint or seal the bare wood
Carpenter bees strongly prefer bare, weathered, and unfinished wood. A coat of paint is the single most effective long-term deterrent; a hard polyurethane or exterior varnish helps but is less protective than paint. Seal the treated boards and any other exposed softwood on the structure so a fresh generation has nowhere inviting to start.
Timing: treat in spring and early summer
Timing decides how well treatment works. Carpenter bees emerge in spring, when overwintered adults become active, mate, and the females excavate or expand galleries to lay eggs. Treating during this active boring window, roughly spring into early summer, hits the adults while they are moving in and out of the holes and picking up dust.
- Spring: adults emerge and begin drilling. Prime time to treat active holes.
- Early summer: females are provisioning galleries with eggs. Continue treating and monitoring.
- Late summer: a new generation emerges from the galleries. Watch for renewed activity.
- Fall: seal and paint bare wood before the bees overwinter inside old tunnels.
If you missed spring, you can still treat active holes through the season and seal in fall, but the highest-impact treatment lands while the bees are actively boring.
Prevent carpenter bees next season
- Paint or varnish all exposed softwood, since bare weathered wood is the main attractant.
- Fill and seal old galleries so returning bees cannot simply reopen last year's tunnels.
- Cap or cover exposed board ends, rafter tails, and fence-post tops where bees like to start.
- Consider swapping the most-targeted trim for a bee-resistant material such as composite or hardwood.
- Inspect eaves, decks, and railings each spring and treat new holes the moment they appear.
- Repair moisture damage promptly, since soft, wet wood is easier for bees to excavate.
When to call a professional and why
Call a pro when galleries are widespread, when the affected wood is high on a second story or steep roofline, when woodpeckers have already torn the wood open, or when you simply want the job done and warrantied. A licensed technician can treat holes you cannot safely reach, apply professional-grade dusts, and often return to seal and re-treat if activity continues.
| Factor | DIY | Professional |
|---|---|---|
| Number of holes | A few, easy to see | Widespread across many boards |
| Height and access | Ground level or short step stool | Second story, roofline, or ladder work |
| Existing damage | Minor, wood still sound | Woodpecker damage or rot present |
| Products | Consumer dust and duster | Professional-grade dusts and equipment |
| Typical cost | Cost of a duster and dust | Modest single-visit fee; varies by access and extent |
| Follow-up | You monitor and reseal | Return visits and treatment often included |
Because the damage compounds year over year and attracts woodpeckers, an early professional treatment on a badly infested structure often costs less than repairing a board that has been tunneled and torn open over several seasons. See our pest control cost guide for what to expect before you book.
Get professional carpenter bee help
For extensive galleries, high or hard-to-reach wood, or damage that woodpeckers have already started, compare license-verified pest control pros in your area and request a free quote. Check our pest control cost guide for typical pricing, and if stinging insects like wasps are also a concern, read our guide on how to get rid of wasps and hornets so you know which pests need which treatment.
Run a pest control company? List your business on PestPin or see how our pro plans work to reach homeowners searching for carpenter bee treatment in your service area.
Frequently asked questions
Are carpenter bees dangerous?
They pose little danger to people. The males that hover and dart aggressively cannot sting at all, and the females can sting but are docile and rarely do unless handled. The real danger is to your wood, since their galleries weaken structural boards over time and attract woodpeckers.
How much damage do carpenter bees cause?
A single season of one bee is minor, but the damage compounds. Females reuse and extend the same galleries year after year, so a favored board can end up with many interconnected tunnels that weaken it. Woodpeckers digging out the larvae and moisture entering the tunnels make it worse.
How do I tell a carpenter bee from a bumblebee?
Look at the abdomen. A carpenter bee has a shiny, hairless, solid-black upper abdomen, while a bumblebee is fuzzy with yellow bands. Carpenter bees also drill perfectly round half-inch holes in bare wood and leave sawdust below them; bumblebees do not damage wood.
Should I plug carpenter bee holes right away?
No. Sealing a hole immediately traps live bees that will chew a new exit through the wood, and it stops the insecticidal dust from spreading through the gallery. Treat the hole first, wait several days for the bees to die and carry the dust deeper, then plug it.
What is the best time of year to treat carpenter bees?
Spring through early summer, while the adults are actively emerging, mating, and boring. Treating during this window hits the bees as they move in and out of the holes. You can still treat active holes later in the season, but spring is the most effective.
What kills carpenter bees in the wood?
An insecticidal dust labeled for carpenter bees, puffed directly into each hole with a hand duster, works best. Bees walking through the treated gallery pick up the dust and carry it deeper, reaching larvae a spray cannot. Plug and paint the wood afterward to prevent reinfestation.
How do I stop carpenter bees from coming back?
Paint or seal all bare softwood, since weathered unfinished wood is the main attractant, and fill old galleries so returning bees cannot reopen last year's tunnels. Inspect eaves, decks, and railings each spring and treat any new holes right away.
Do carpenter bees attract woodpeckers?
Yes. Woodpeckers detect the larvae inside the galleries and tear open the wood to eat them, turning clean half-inch holes into ragged, gaping damage. Treating the bees early removes the food source and helps prevent the woodpecker damage that follows.