I don't know if you have been following things but some disease is thinning honey bee hives---worldwide but especially in the US---in staggering numbers. The bees leave the hive and never return. Honey bees are the major pollinators of the fruits and many vegetable we eat and are super critical to global food supplies. In fact they are responsible for at least 1/3 of it. Here is a USDA piece on Colony Collapse Disorder. It is a really big deal.
Obviously you do not want a hive in your wall but call around. Ag extension or your university entomology department will find you a beekeeper willing to come and move them. Please do not kill them.
Depending on where you are, beekeepers or honey farms may be listed in the phone book. Here is the URL for the honeybee conservancy. They may have resources and ideas.
Here is a wild idea. Do you have room on your property for a hive or two? My second cousins raise honey and there is nothing like fresh honey or chewing on a piece of honeycomb. In all the years I visited, and even reaching my hand in a hive, I was never stung. I have been stung encountering bees elsewhere though. American honeybees are really fairly docile creatures.
Did you know that St. Valentine is the patron saint of beekeepers and not just sappy greeting cards with hearts? You must be really sweet people to attract honey and bumble bees. Are you sure they are bumble bees and not carpenter bees by the way? I have found a lot of the latter around old construction for some reason. The make perfectly round holes in wood members. They seldom sting but are very aggressive.