At 10:07 AM 4/5/02 +0100, you wrote: >I am not particularly surprised that they could do this , but I would like >to understand the mechanism whereby they 'know' where a blocked up hole is >so that they can unblock it. I'm using a combination innercover, insulated and ventallation top box this past winter. It includes an upper entrance similar to the Bee Culture article last year on overwintering single deeps. I was a bit concerned when the bees nearly sealed the openings with propolis. But now that we have some warmer weather they have mostly opened them again. Seems if you give them something they can manage (not too big an opening) they do pretty well on their own. Time will tell, this past winter wasn't a good test case. -Tim