Carpenter Bee

Actual Size: ½ to 1”

Characteristics: Large bees with hairless abdomens and black and yellow coloring

Legs: 6

Antennae: Yes

Habitat: Instead of making nests, females dig holes in softwood and despot their eggs inside

Habits:

• Do not live in nests and colonies, unlike most bees.
• Cause damage to decayed wood by boring into it, not by eating it.
• Male carpenter bees are very aggressive, even though they don’t have stingers.

Carpenter Bees in Wisconsin

Carpenter bees are named after their ability to drill into wood, where they carve out chambers and nurture their offspring. They’re also one of the largest native bees in the United States, similar to queen bumblebees. These bees are commonly found throughout the United States, including within Wisconsin. Even though they don’t eat wood, they often weaken structures by tunneling through dry or damaged lumber.

Carpenter Bee Habitat

Carpenter bees are solitary creatures, so singular bees will create their own nests in trees, eaves, or the sides of buildings. Both males and females spend the winter inside old tunnels, but emerge in spring to reproduce. After mating, the female searches for a suitable wooden surface to build her nest, while the male hovers nearby and guards her. The female bee will use her mandibles to carve out a gallery and stock it with a blend of pollen and regurgitated nectar known as “bee bread.” Once this has been completed, she will lay an egg, and seal the chamber with chewed wood pulp. Signs of an infestation often include piles of sawdust and pollen accumulating beneath the areas where they’ve burrowed.

Carpenter Bee Behaviors, Threats, or Dangers

Female carpenter bees are typically not aggressive, but will sting when they feel threatened. Anyone allergic to bee venom should seek medical attention immediately if stung. Males on the other hand can be highly defensive, especially when guarding their nests, despite the fact that they do not have any stingers. While these bees contribute to pollination, they are also capable of causing structural damage. They love to tunnel into wooden siding, decks, railings, windowsills, fences, and outdoor furniture. A single bee’s burrowing usually only causes minimal harm, but when many bees repeatedly tunnel over time, the damage can become significant. If you suspect an infestation has occurred on your property, reach out to a pest control professional as soon as possible.