I just discovered I have some Bumbles in one of my bird houses!! I put up a wood pecker box about 15 feet up in a tree. I filled it will saw dust because I was told the wood peckers like to clean out their nest site. Well no wood peckers moved in but I now have some Bumble bees! They must be hot this afternoon because they are fanning at the front of the box just like my honey bees are.