It may also be possible that what you have are Carpenter Bees. They look very much like a Bumble Bee but have no hair (no yellow/black fuzzy stuff
. They normally tunnel into the wood just under the roof line to lay their eggs. They are particulary attracted to bare wood. If you google for Carpenter Bees, there is a lot of information on how to control them. The good news is that they are basically harmless. The males do not have stingers and the females will only sting if they improperly handled.