For the last week or so I've noticed my two strong hives clustering around the entrance in the afternoon and evening, sometimes beginning to hang down off the bottom board and today actually blocking off the entrance to one of the hives. At first I though it may be due to hot weather, but today was rainy (finally!!!) and 70 degrees (blessed relief). So I'm wondering if anyone has thoughts on this bit of bee behavior? Too crowded? Both hives had a few empty frames in their brood boxes and both full and empty supers above an excluder.