Carpenter bees have metal-like, black color and no yellow marks. Their length is 2 to 2.5 inches. They have solitary behavior and cannot prepare wax. From flower to flower, they can travel long distances. The nests these bees make are in flower stalks or wood. As they make tunnels in solid wood, they are so called. There exists a pile of sawdust near the nest entrance.
Well better this than other sucky types of bees like bumblesbee, honeybees or the damnest of all bees, YBs.