Honey bees are cold-blooded insects. Like all insects, honey bees are ectothermic, which means their body temperature is influenced by the external environment rather than being regulated internally. They cannot generate heat internally like warm-blooded animals (endotherms) such as mammals and birds. Instead, honey bees rely on external heat sources, such as sunlight, to warm themselves and maintain their body temperature. In cooler temperatures, honey bees can cluster together in their hive to generate heat collectively and maintain warmth.