It was in the 70's last week in Williamsburg, which means the bees all broke cluster and enjoyed some cleansing flights. There is a risk with the warm/cold cycle of days as we go into January and February. The bees will use more resources (honey) when they break cluster. To help them through the winter I put dry sugar on the inner cover. This absorbs moisture, as well as provides emergency food. How much they use it varies by hive (size, stores, etc). The hive in this photo went into winter very strong and I was not surprised to see some bees on the inner cover when I checked them.