Quick answer
Carpenter bees drill into bare or weathered wood. Treat the holes, seal them, and finish the wood. Here’s how:
- Look for perfectly round, ½-inch holes in bare wood — decks, eaves, fascia, railings and fences.
- Treat active holes with an insecticidal dust labeled for carpenter bees.
- Wait a few days so returning bees contact the dust, then plug the holes and paint or stain over them.
- Paint or stain all bare wood — it’s the best long-term deterrent.
- Act in spring (April–May), when bees are drilling and reusing holes.
Lots of holes, sawdust piles under them, or woodpeckers tearing at your trim mean an established problem — treating and sealing now saves wood repairs later.
Carpenter Bee or Bumblebee? How to Tell
They look alike at a glance, but only carpenter bees damage wood. The abdomen is the giveaway:
| Carpenter bee | Bumblebee | |
|---|---|---|
| Abdomen | Shiny, mostly hairless black | Fuzzy with yellow bands |
| Size | About ¾–1 inch | Similar size |
| Where you see them | Hovering around eaves, decks, fences and wood siding | On flowers; nests in the ground or old rodent burrows |
| Damage | Bore perfectly round, ½-inch holes into wood to lay eggs | No wood damage |
| Stings | Males can’t sting (but hover aggressively); females rarely sting | Can sting if the nest is disturbed |
| What to do | Treat and seal the holes; paint or stain the wood | Usually leave alone — they’re valuable pollinators |
Signs of carpenter bees: round holes about the width of your finger, coarse sawdust under them, and yellowish-brown stains below the entrance.
Not sure what’s drilling your deck? Text a photo — a licensed technician will tell you for free.
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How Bad Is Your Carpenter Bee Problem?
Each hole leads to a tunnel that can run several inches through the wood — and bees reuse and extend them every year. Tick everything that applies:
30-second carpenter bee check
Why Carpenter Bees Come Back Every Spring
- Spring emergence. In Chicagoland, adults become active in April and May, mate, and females drill new tunnels or reopen old ones to lay eggs.
- Winters weather the wood. Freeze-thaw cycles and moisture leave decks, fences and trim bare and weathered — exactly the wood carpenter bees prefer.
- They reuse tunnels. The same galleries get extended year after year, so untreated damage keeps growing.
- Woodpeckers make it worse. They tear into the wood to reach the larvae inside, turning small holes into big repairs.
Step-by-Step: How to Get Rid of Carpenter Bees Yourself
For a few holes you can reach safely, this plan works. Timing matters: treat first, wait, then seal.
Find the Active Holes
On a warm spring day, watch where bees go in and out. Fresh sawdust below a hole means it’s active.
Dust the Holes
Puff an insecticidal dust labeled for carpenter bees into each hole, following the label. Evening is best, when bees are inside.
Leave Them Open a Few Days
Returning bees pick up the dust as they crawl in. Sealing too early can trap bees inside, and they’ll chew a new exit.
Plug and Seal
Fill each hole with a wooden dowel, wood putty or caulk.
Paint or Stain
Finish all bare wood — including the undersides of railings, fascia and deck boards. Painted and well-sealed wood is far less attractive to carpenter bees.
Check Again Next Spring
New adults emerge in late summer and overwinter in tunnels, so look for new holes when bees become active again in April.
Be careful on ladders and always follow the product label. Male carpenter bees hover close but can’t sting.
Holes up at the eaves or second floor? A licensed tech can treat and seal them safely.
Get a Free Quote — We Call Back in 15 MinOr call (708) 907-1872 · Mon–Fri 8–5, Sat 9–12
What Not to Do
- Plugging holes without treating them first. Bees inside simply chew a new way out.
- Relying on surface sprays. They don’t reach the bees and larvae deep in the tunnels.
- Leaving wood bare or weathered. Untreated wood invites new tunnels every spring.
- Ignoring woodpecker damage. It means larvae are inside and the wood is being opened up further.
- Spraying flowers or bumblebees. Bumblebees and other bees are important pollinators and don’t damage wood.
Why DIY Carpenter Bee Control Often Fails
- The holes are out of reach. Eaves, fascia and second-story trim are hard and risky to treat from a ladder.
- Tunnels run deep. Galleries can turn and branch several inches inside the wood.
- The timing is off. Sealing too early or treating too late lets the next generation survive.
- The wood stays bare. Without paint or stain, new bees move right back in.
When to call a professional: you have many holes, holes high on the house, woodpecker damage, or bees returning to the same spots year after year.
What Carpenter Bee Treatment Costs in Chicagoland
Dust, a duster and wood putty are inexpensive for a few holes you can reach. For larger or higher problems, professional treatment is safer and more thorough.
Most EcoWall carpenter bee treatments run about $175–$400, depending on how many holes there are and how far the galleries extend. We confirm the exact price after inspection, before any work begins.
What to Expect From a Professional Treatment
- Inspection: every wood surface checked — eaves, fascia, decks, railings, fences and siding.
- Gallery treatment: professional dust applied deep into each active tunnel.
- Sealing: holes plugged at the right time so bees can’t reuse them.
- Guarantee: if carpenter bees return to a treated area within 90 days, we re-treat and re-seal at no charge.
How to Keep Carpenter Bees From Coming Back
- Paint or stain all exposed wood, including undersides
- Keep the finish maintained — touch up peeling paint
- Use painted, pressure-treated or composite boards for repairs
- Fill old holes so they can’t be reused
- Check eaves, decks and fences for new holes every April
- Fix woodpecker damage promptly
Carpenter Bee FAQ
Do carpenter bees cause structural damage?
Individual holes look minor, but the tunnels behind them are reused and extended every year. Over several seasons — especially with woodpeckers digging for larvae — carpenter bees can seriously weaken fascia boards, deck railings and trim.
Do carpenter bees sting?
Male carpenter bees can’t sting, even though they hover and dive at people. Females can sting but rarely do unless they’re handled or trapped.
When are carpenter bees active in Chicagoland?
Adults become active in April and May, when they mate and drill or reopen tunnels. A new generation emerges in late summer and spends the winter in the tunnels.
Should I plug carpenter bee holes?
Yes — but treat them first. Dust the holes, leave them open a few days so returning bees contact the treatment, then plug them with a dowel, wood putty or caulk and paint over them.
Do carpenter bee traps work?
Traps can catch some bees, but they don’t treat the larvae already inside your wood. They work best alongside treating the holes and painting or staining the wood.
How much does carpenter bee treatment cost?
Most EcoWall carpenter bee treatments range from $175–$400, depending on the number of holes and how far the galleries extend. We provide free inspections and confirm the price before any work begins.
Carpenter Bee Control Near You
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