We had a warm day so the girls were flying. In front of the hive was a bunch ~100 bees that were sitting on the grass. This is occurring in front of both hives. Now that night is here I checked again and they are still there. They don't show signs of DWV ie they have normal wings. I don't think they are drones. This is the first warm day in a couple of weeks. Is this normal or is there a problem I should look for in the hive? The bees on the ground will freeze tonight and they are not going back in.