Getting rid of carpenter bees requires a two-pronged strategy: driving out or eliminating active tunnelers, then sealing and finishing the wood so new generations can’t move in.
Because carpenter bees don’t actually eat wood—they only chew tunnels to lay eggs—surface sprays rarely kill them. Here are the five most effective ways to clear them out and protect your home.
1. Treat Active Tunnels with Insecticidal Dust or Aerosol Foam
- Best for: Active infestations with visible entry holes.
- How it works: Liquid sprays quickly dry or wash off, but insecticidal dust (like boric acid or deltamethrin) or expanding foam pesticide coats the entire inside of the gallery. When bees crawl through the tunnel, they pick up the dust on their legs and bodies.
- Pro tip: Apply treatment at dusk or early morning when the bees are inside and inactive. Wear protective eyewear and gloves.
2. Hang Wooden Carpenter Bee Traps
- Best for: Non-toxic, continuous population control.
- How it works: These are simple wooden boxes with pre-drilled angled holes that mimic natural bee tunnels. When bees enter the hole looking for a nest, they fall into a clear plastic bottle attached to the bottom. They head toward the light at the bottom of the container and cannot fly back out.
- Where to place: Mount traps high on sunny corners, eaves, or deck posts right near existing activity.
3. Spray Natural Essential Oil Deterrents
- Best for: Eco-friendly repellents that preserve pollinators.
- How it works: Carpenter bees have a strong sense of smell and strongly dislike citrus oil, peppermint, tea tree oil, and bitter almond oil.
- DIY recipe: Boil citrus peels (lemons, oranges, grapefruit) in water for 20 minutes, let it cool, and pour into a spray bottle. Spray directly into entry holes and across bare wood surfaces every few days during peak spring nesting season.
4. Plug and Seal Every Tunnel Opening
- Best for: Stopping re-infestation.
- How to do it: Once you are sure active bees inside are dead or gone, fill the holes. Insert a wooden dowel or steel wool into the tunnel entrance, then cap it with exterior wood putty, caulk, or wood filler.
- Crucial step: Wait 24–48 hours after insecticidal treatment before sealing. If you plug a hole while a live female is still inside, she will chew a new exit hole right through your timber to get out.
5. Paint or Stain All Exposed Wood Surfaces
- Best for: Long-term preventative defense.
- How it works: Carpenter bees strongly prefer unpainted, weathered softwoods (pine, cedar, redwood). Applying a thick coat of primer and exterior paint creates a hard shell that makes boring difficult and unattractive to female bees. High-quality exterior stain or polyurethane sealants also work well if you prefer a natural wood look.
Good to know: The aggressive bees hovering near your face around deck posts are males. Male carpenter bees have no stinger and are completely harmless. Only females can sting, and they rarely do so unless directly squeezed or handled.
