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. That’s why we advocate understanding the biology of a species and the use of integrated pest management.
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 the face.
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.
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. Note: The frass (excrement) below these holes may contain small quantities of yellow pellets.
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 under-side of eaves), against wood siding, in wooden fences, mailbox posts, and even hardwood handles of tools.
First, consider deterring them, by coating all exposed surfaces of wood with paint or stains.
Once holes are created, small sections of wooden dowel or wood-fill can be placed in nest entrances to prevent future nesting. If blocked after the female exits, she will drill a new hole nearby. In extreme cases, cover wood with plastic or metal.
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 will not cause damage to the home, and can be eliminated by carefully removing, destroying, or treating the wood.
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 vessel (glass or plastic). Do-it-yourselfers can find guidance for making these online. Make sure trap wood includes an “existing” nest opening (a hole drilled into wood at an upward angle).
Caution is recommended, because carpenter bee nests are often found in areas where you’ll need a ladder. Instead, consider a professional pest control operator with experience in carpenter bee elimination, especially if a large population of bees have cause substantial damage.
For more information on carpenter bees, see Get Rid of Carpenter Bees? Yes, Please!