I have a top bar hive in which I installed a 3 lb package March 31. Things have gone well in terms of comb-drawing and population buildup. It's rainy and 56 degrees F here today, and it's been rainy and cool for several days. On the front of the hive, just above the entrance, a large number of bees have formed a cluster roughly square-shaped and about 8"x8". Foraging bees are actually having to push their way through the cluster to get in and out. As a brand new beekeeper, I am mystified by this behavior. Can anyone help me out? Thanks.