Somehow or other I seem to have accidentally deleted what I wrote a moment ago. It's not honeybees as they're not ground nesters. There have been a few rports of wasp nests overwintering recently in the south, but basically they and bumblebees are both annual nesters, so it should be gone as soon as we get some cold weather; it really is very later for them still to be functioning at all. Meanwhile, if you don't bother them, they won't bother you; you've been there six weeks without noticing them, after all. If you really must kill them, pour a bucketful of soapy water down the hole.
