The hairy, bluish-black bees you see visiting flowers or hear buzzing by each spring are female carpenter bees. They are over one inch long and about as wide as your thumb. Female carpenter bees are capable of stinging, but are not normally aggressive. They do not sting unless trapped, stepped on or otherwise endangered. Male carpenter bees are similar in size to females, but are blond or tan-colored.
Carpenter bees nest in wood, such as dead tree trunks, firewood or exposed wood on structures.
They excavate a tunnel about ten inches long within the wood. The female bee then visits local flowers to gather pollen and nectar. The female rolls the pollen into a ball, and pushes it to the back of the tunnel where she lays an egg. She loosely plugs the end with sawdust chips and other materials, forming a chamber roughly one inch long. She then goes to get more pollen and repeats the process until the tunnel is filled with chambers full of growing bees.