Carpenter bees generally look very similar to bumblebees, but they can be distinguished by the fact that the abdomen of the carpenter bee is usually entirely black and hairless. In contrast, the abdomen of a bumblebee is covered in hair, and it tends to contain at least some yellow coloring.
The other easy way to distinguish between the two species is by their nesting habitats. If numerous bees are seen coming out of holes in wood or flying near the eaves of a building, they are most likely carpenter bees. These bees get their name from the fact that they drill holes and build their nests inside wood. On the other hand, bumblebees are solitary insects that live in burrows dug underground.
Carpenter bees rarely pose a problem for humans, other than the damage they can cause in wood structures. Male carpenter bees may hover near people and fly at them if they come close to the nest site, but they don't have the ability to sting. Female carpenter bees do have the ability to sting, but they very rarely do so if seriously provoked or threatened. The most common problems associated with carpenter bees is structural damage, as not only do they drill holes in wood, but they also cause stains on buildings by defecating on the walls below their nest.