How to Get Rid of Carpenter Bees
To get rid of carpenter bees, treat the existing nest holes, then plug and seal them once the bees are gone, and protect bare wood with paint or finish so they stop drilling. Deterrents and good timing in spring keep new bees from returning.
By Lara Holm
·Staff Writer ·
·
5 min read
To get rid of carpenter bees, treat the nest holes, then seal and protect the wood so they can’t drill back in. Carpenter bees tunnel into bare or weathered wood to raise young, so the lasting fix combines treating active holes, plugging and sealing them once the bees leave, and finishing exposed wood with paint so new bees look elsewhere.
How do I know it’s carpenter bees?
Carpenter bees look like large bumblebees but have a shiny, mostly hairless black abdomen rather than a fuzzy one. The tell-tale sign is a nearly perfect round hole, about half an inch across, drilled into wood, often with coarse sawdust below it and yellowish staining nearby. You may see bees hovering around eaves, decks, railings, fascia boards, and fence posts, especially in spring. Unlike termites, they don’t eat the wood; they excavate tunnels to nest.
Where do carpenter bees nest and why?
They prefer bare, unpainted, or weathered softwoods such as cedar, pine, redwood, cypress, and fir. Sunny, south-facing surfaces and horizontal undersides (eaves, deck rails, window trim) are favorites. Because they return to good nesting wood year after year and reuse old tunnels, an untreated spot tends to get worse over time.
How do I treat the nest holes?
Treating the galleries where the bees and larvae live is the core step:
- Work in the evening when bees are inside the tunnels and less active.
- Apply an insecticide labeled for carpenter bees (dusts and sprays made for this purpose are common) directly into each hole, following the product label exactly.
- Leave the hole open for a few days so bees moving in and out spread the product through the tunnel and to the larvae.
- Repeat if you still see activity, and re-treat reused holes the following spring if needed.
Wear eye protection and avoid standing directly under a hole while treating overhead wood.
When and how do I plug the holes?
Sealing is what prevents reuse, but timing matters. Plug holes only after the active bees are gone, typically a few days after treatment, or in late summer once the new generation has emerged, so you don’t trap live bees that will simply bore a fresh exit. To seal:
- Push a wooden dowel coated in wood glue into the hole, or fill it with wood putty or caulk.
- Some people pack a bit of steel wool or aluminum foil in first, then caulk over it.
- Sand smooth, then paint or finish the patch so it blends and resists future drilling.
What deterrents and prevention actually help?
Once holes are handled, make the wood unappealing:
| Approach | How it helps | Keep in mind |
|---|---|---|
| Paint or polyurethane finish | Smooth finished wood is far less attractive than bare wood | Stains and oils help less than solid paint |
| Plug & seal old holes | Stops reuse of existing tunnels | Do it after bees are gone |
| Scent deterrents (e.g., almond or citrus oil) | Odor discourages nesting | Temporary; must be reapplied, best as a supplement |
| Carpenter-bee traps | Capture hovering adults near nest sites | Works alongside sealing, not instead of it |
| Swap to hardwood / treated lumber | Less inviting for drilling | Practical for replacement pieces |
Scent-based deterrents such as almond oil are popular because the smell bothers the bees, but their effect fades in a few months and needs reapplying through spring, so treat them as a helper rather than a standalone cure.
What damage do carpenter bees cause?
A single new tunnel is usually only a few inches long and does little harm on its own. The problem is repetition over the years: because carpenter bees reuse and extend old galleries each season and multiple females may nest in the same board, tunnels can branch and lengthen over time, weakening railings, fascia, and trim. That slow expansion is why treating and sealing early is worth the effort rather than waiting.
There is also a secondary problem. Woodpeckers hunt carpenter-bee larvae and will peck open the wood to reach them, turning a few tidy holes into ragged, torn-out sections of siding or eave. And the yellowish staining you often see below the holes is waste that can mark painted surfaces. Treating the galleries removes the larvae that attract woodpeckers, which is another reason to deal with active nests promptly instead of leaving them.
Are carpenter bees dangerous?
They are far more alarming than dangerous. The large bees that dive-bomb you near a nest are usually males, which have no stinger and are only guarding territory. Females can sting but are docile and generally only do so if grabbed or trapped. Carpenter bees are also important pollinators, so where they aren’t damaging structures it’s reasonable to leave them be and simply protect vulnerable wood.
When should I call a professional?
Call a licensed pest-control professional if the nesting is extensive, if holes are high up or hard to reach safely, if you find many galleries suggesting years of activity, or if woodpeckers are tearing at the wood to reach larvae and causing further damage. A pro can treat galleries you can’t access and recommend repairs. Always follow the label on any pesticide, and if you are sensitive to stings, let someone else handle close-up work or hire a pro.
Frequently asked questions
What attracts carpenter bees to a house?
Carpenter bees are drawn to bare, weathered, or unpainted softwood like eaves, decks, fascia, railings, and fence posts. South-facing sunny wood is especially appealing for nesting.
Do carpenter bees sting?
Male carpenter bees hover aggressively but have no stinger. Females can sting but are not aggressive and usually only sting if handled or trapped.
What is the best time to treat carpenter bees?
Treat in spring when bees first become active and again as needed, and treat holes in the evening when bees are inside. Sealing works best after the current generation has emerged, often late summer.
Should I plug carpenter bee holes right away?
Treat the hole first and wait a few days so bees spread any product through the tunnel; plugging too soon can trap live bees that bore a new exit. Then seal the hole.
Do natural repellents like almond oil work on carpenter bees?
Some people use almond or citrus oils as a deterrent because the scent bothers the bees, but the effect is temporary and must be reapplied, so it works best alongside sealing and painting.
Are carpenter bees worth saving as pollinators?
Carpenter bees are valuable pollinators, so when they aren’t damaging your home, it’s best to leave them alone and focus on protecting the wood they target.
