Ectotherms cannot regulate their own body temperature internally, so their temperatures will fluctuate with the environments, therefore ectotherms rely on behavioural mechanisms to control their temperatures.
Honey Bees Edit
Unlike most bees, which hibernate during colder months, honey bees remain active all winter long despite the freezing temperatures.
A honey bee colony’s ability to survive the winter depends on their food stores of honey. Once the colony begins to run out of honey, the worker bees force the useless drones from the hive, to maintain the food store.
As temperatures drop, the honey bee workers form a cluster around the queen and brood, keeping them warm. Bees on the inside of the cluster can feed on the stored honey. If surrounding temperatures rise, the bees on the outside of the group separate a bit, to allow more air flow. As temperatures fall, the cluster tightens, and the outer bees pull together.
As it gets colder, the worker bees actively generate heat within the hive, by feeding on honey for energy and then shivering. They vibrate their flight muscles but keep their wings still, raising their body temperatures. With thousands of bees shivering constantly, the temperature at the centre of the cluster will warm up considerably.
When the workers on the outer edge of the cluster get cold, they push to the centre of the group, and other bees take a turn shielding the group from the cold.