We've had a really cold winter this winter and today was the first day that I checked on my 2 hives. The first hive had plenty of honey in it and plenty of bees (almost like it was summer time). The second one had plenty of honey but a lot less bees. In comparison, I would see the "big" hive with 30 bees flying around the front and only 2-5 on the "small" hive. They were both healthy before the winter. What could be my problems or do hive just kind of die off in numbers during the winter?