Many

Carpenter bees (Xylocopinae subfamily) are important pollinators, especially of open-faced flowers, though they are also known to "rob" nectar by boring holes in the sides of flowers with deep corollas (thus not accomplishing pollination). The smaller species tunnel into pithy stems to build their nests. Other species bore holes in wood and can become pests in wood construction.

Carpenter bees are often mistaken for bumblebees. They are similar in size and coloring. The primary physical difference is on the abdomen. Carpenter bees have a shiny black abdomen. Bumblebees have a fuzzy abdoment with some yellow coloring.

Similar to termites, carpenter bees are a problem for wood-framed homes. They make nests by tunelling into wood. They make an initial upward hole in any overhang. Then, they make many horizontal tunnels. Because of their pollination skill, some people allow carpenter bees to stay around the home in the early spring, repairing the damage later. There are also programs for attracting carpenter bees to areas they are needed by supplying them with suitable nesting holes in blocks of wood.

Carpenter bees spend the winter as adults inside abandoned nests. Then, they emerge in the spring to mate and lay eggs. The female will usually bore longer tunnels in the nest for the eggs while the male collects pollen for larvae feed. Active nests in a home can have considerable damage in just a few years.

Carpenter bee nests are rather easy to spot. They bore the opening hole directly up into the bottom of an overhang. The entrance hole is about the size of adult human's finger. Because the female continually bores longer tunnels, there is usually a collection of fresh sawdust below the hole. Also, the sound of a boring carpenter bee is very loud and can be heard easily. To deter carpenter bees from making nests in your home, you should keep all wood painted or stained. Paint is a better deterent than stain, but it is important to avoid having bare wood available as it is very inviting to a bee looking for a place to start a new nest.

Male carpenter bees are aggressive and will challenge anyone, including humans, that come near their nests. However, the males do not have stingers and cannot cause any real harm. The female carpenter bees are far more docile, but have the ability to cause a painful sting.