In the winter, most bees stay in the hive, kept warm by heater bees and living off honey stored there. Bees can remain active through the winter, but the queen can be the only bee to survive until spring since she is the only bee to produce offspring. The other bees protect the queen from hunger and cold.
Bees group together around the queen and vibrate to increase the heat in the hive. Stored honey supplies the food, and useless drones are forced out of the hive to provide more for the remaining bees. Heater bees have several jobs that include entering empty cells and vibrating to heat the brood cells around them or pressing the thorax against a brood cell while vibrating their muscles. Because bees are cold-blooded insects, they cannot fly when their body temperature reaches around 95 degrees Fahrenheit. For this reason, bees remain inside the hive when the outdoor temperature drops to around 50 degrees Fahrenheit. Inside the hive, they rotate positions because the inner part of the hive is more crowded and warmer. Because the heater bees constantly vibrate to warm the hive, other bees sometimes bring them food to replenish the energy they are expending through their constant activity.