Yesterday here in SW PA it was in the low 70's. A great opportunity to head out to the beeyard. Amazingly, I have bees in 8 of the 9 hives I prepared for winter (no treatment for 2 years). In the fall I suppported each hive's food stores by placing sugar on notebook paper on the top frames of each hive. I noticed that one of these hives yesterday had seemed to consume most of this sugar and was clustered in daisy chain fashion on top of the inner cover and the top bars through the opening of thhe inner cover. I placed more sugar on the inner cover. This week the predicted temps. are to decrease to the 20's and 30's. What is this behavior and what should I be looking for?
Typically, bees that are clustered will hang together and in late winter they will be clustered at the very top of the hive. As you lifted the inner cover what you were seeing was the effect of the cluster being separated.
You should check the wt of the colony and make sure they are close enough to the remaining honey or sugar that they don't run out of food. By placing sugar above them I would imagine they are going to have enough food to make it for the next several weeks.