What are those large bees that fly near your eaves, or under your deck railings? Most often the oversized bees are Carpenter Bees. Carpenter Bees resemble bumblebees, but tend to be a bit larger and their abdomen is shiny, black and hairless. If you see a bunch of large bees hovering near your eaves, you probably have Carpenter Bees. They are very common throughout the spring and summer. They emerge in spring, mate, and work on their tunnels or excavate new ones as brood chambers for their young. Usually the new adults emerge in August, feed on nectar and return to their tunnels to over-winter.