The bees are arranged in their specific winter configurations, so this is the time to make any final adjustments needed to give the bees the best chance of winter survival.
The cluster will remain inside the hive throughout the winter, only leaving for cleansing flights on the occasional warm day. When temperatures dip below 57˚ F bees will cluster in the hive, and when a bee’s body temperature falls below 50˚ F they become motionless. Not to worry though, a honey bee’s biology allows it to survive such cold conditions. When temperatures drop 23˚ F or below, the bees on the inside of the cluster begin vibrating their wings to generate heat. The bees along the outer shell of the cluster remain motionless, acting as a layer of insulation. The optimal core temperature of a cluster is 95˚ F while the exterior shell temperature hovers around 48˚ F. To keep any bees from getting too cold, the cluster rotates around the queen, exchanging outer core bees for inner core bees.
In addition to ensuring that the bees are properly arranged for winter and all equipment is winterized, one last varroa mite treatment is being administered, by dribbling oxalic acid syrup, to ensure the mite levels are as low as they can be going into winter and are focused on staying warm and conserving food. By the end of the season, the bees have ceased production of brood, meaning the mites have nowhere to hide and are most vulnerable to treatment.
Any dead bees at the hive entrance are a good sign, as it is an indication that the colony is alive and is actively cleaning out its dead.