Carpenter Bees

Carpenter bees are spring pollinators but are considered pests when they damage wooden structures. Birds like woodpeckers add to damage when they search for bee larvae and create large openings in the wood.

Categories: Pollinators • Bees and Wasps • Wood Damage

Bumble bee on a flower
Eastern bumble bee

Behavior

Carpenter bee queens work alone to excavate long tunnels in wood, creating galleries to raise new bees.

Bumble bee queens create colonies in existing protected cavities. Workers cooperate to raise hundreds of new bees.

carpenter bee on a flower

Should I worry about carpenter Bees?

Do carpenter bees sting? 

Carpenter bee males hover near female nesting sites, and will chase off other males that approach the nest, and may mock-attack humans. While they appear threatening, males are not dangerous because they possess no stinger. Females carpenter bees are reluctant to sting but will do so if threatened or trapped.

Damage to wooden Structures

Carpenter bees are considered pests when they damage wood. Unfortunately, birds like woodpeckers add to damage when they search for bee larvae and create large openings in the wood. Females carpenter bees create a smooth, round opening 3/8 to ½ of an inch in diameter, and tend to return to the same area, as will her later generations.

Carpenter Bee Biology

Carpenter bees are common spring and summer insects in the eastern United States. You may notice females excavating holes in wooden structures, or see a male “buzz” or “dive bomb” passersby. Like carpenter ants, carpenter bees do not eat wood, but rather use it. Females excavate (chew and remove) tunnels to provide a safe place for egg laying. Carpenter bees are solitary and don’t form colonies, but many females may nest in the same area. Despite being a nuisance pest of structures, they are also pollinators.

What do carpenter bees look like?

Adults are robust, 3/4”- 1” long (25mm) with yellow hairs on the thorax, and a shiny, non-fuzzy black abdomen. Males have a yellow patch on their faces.

Why do I have carpenter bees? 

Because you probably have wood! Carpenter bee females prefer to build their nests in soft wood that lacks a coating of paint but are capable of nesting in many kinds of wood protected with various coatings. They often nest in soffits (the underside of eaves), against wood siding, in wooden fences, mailbox posts, and even hardwood handles of tools.

How do I get rid of carpenter bees?

Paint Wood Surfaces

Coating all exposed surfaces of wood with paint or stains will make them less appealing to the carpenter bees.

Block Existing Holes

If carpenter bees have already created holes, small sections of wooden dowel or wood-fill can be placed in nest entrances to prevent future nesting. If the holes are blocked after the female exits, she will drill a new hole nearby. In extreme cases, cover wooden surfaces with plastic or metal.

Trap Wood

Another option, known as trap wood, is providing a piece of inexpensive, unpainted wood near known nest sites, making sure that this trap wood is oriented in the same direction as structural wood. Bees that nest in this wood instead will not cause damage to your home and can be eliminated by carefully removing, destroying, or treating the wood.

Carpenter Bee Traps

Make a Carpenter Bee Trap
If you want to make your own trap you can find instructions on wikiHow.

There are also carpenter bee traps meant to draw in females through a pre-drilled hole. When bees attempt to exit the trap, they enter a clear container (glass or plastic). Do-it-yourselfers can find guidance for making these online. Make sure the trap wood includes an existing nest opening (a hole drilled into the wood at an upward angle).

Related Links and Publications