What Are Carpenter Bees and Why Are They Drilling into Your House?
If you’ve noticed perfectly round holes in your home’s wood siding, deck, or trim, carpenter bees could be the culprits. These large, buzzing insects are often mistaken for bumblebees—but while they don’t live in hives, they can still cause a surprising amount of structural damage.
Let’s take a closer look at what makes carpenter bees unique, how to identify their activity, and what you can do to protect your home.
What Are Carpenter Bees?
Carpenter bees are solitary wood-nesting bees known for their habit of boring into wood to lay eggs. Unlike honeybees or bumblebees, they don’t build hives or live in colonies. Each female carves out her own tunnel—often in soft, untreated wood.
Quick Facts:
- Size: About ½ to 1 inch long
- Appearance: Large, robust bees with shiny black abdomens (unlike the fuzzy abdomen of a bumblebee)
- Behavior: Buzz loudly, hover near wood surfaces, and return to the same nesting areas year after year
They’re most active in spring and early summer, when females are looking for nesting sites and males hover nearby to protect the territory.
Why Are They Drilling Into My House?
Carpenter bees don’t eat wood—they just excavate tunnels to lay their eggs. They’re particularly drawn to:
- Unpainted or untreated wood (eaves, fascia boards, siding, railings, fences, and decks)
- Softwoods like pine, cedar, and redwood
- Sunny, sheltered areas where the wood is dry and exposed
A single carpenter bee doesn’t cause much damage. But repeated tunneling over multiple seasons can lead to weakened structures, moisture intrusion, and secondary pest infestations (like woodpeckers, which feed on larvae inside the tunnels).
Signs of Carpenter Bee Activity
Not sure if carpenter bees are the problem? Here’s what to look for:
Perfectly round holes
Roughly the size of a dime, often found on the undersides of wood surfaces like railings, eaves, or beams.
Sawdust piles (frass)
Light-colored, fine sawdust beneath holes or on the ground below.
Buzzing and hovering bees
Especially in spring, males patrol the nesting area while females drill and lay eggs.
Stains or streaks
Yellowish-brown stains beneath entry holes, caused by bee waste.
If you’re seeing any of these, there’s a good chance carpenter bees are active on your property.
Are Carpenter Bees Dangerous?
To humans, carpenter bees are more annoying than dangerous.
- Males can’t sting, though they’ll aggressively hover near people.
- Females can sting, but only if provoked or handled.
The real threat is to your home’s wooden structures. Over time, their tunneling can weaken support beams, compromise trim and fascia, and allow moisture or other pests to get inside.
How to Deter Carpenter Bees
Preventing carpenter bee damage starts with making your home less inviting to them.
Paint or seal exposed wood
Bees prefer bare, untreated wood. Applying paint or a high-quality sealant can make surfaces much less attractive.
Repair or replace damaged wood
Don’t leave old tunnels open. Bees may return to the same nesting spot year after year. Plug holes with wood filler or caulk, then sand and seal the area.
Use physical deterrents
Hanging wind chimes, aluminum foil strips, or other moving objects near active areas may discourage bees from nesting.
Consider pressure-treated wood
For new construction or repairs, treated wood is far less likely to attract carpenter bees.
When to Call a Professional
If you’ve got repeated or widespread carpenter bee activity, DIY fixes may not be enough.
At Specter Pest Control, we take a safe, modern, and proactive approach to managing carpenter bees:
- Thorough inspection of your home’s exterior
- Identification of entry points and nesting activity
- Targeted, family-friendly treatments
- Guidance to prevent future damage
