Heater Bee
Lexikon
Heater bees, also called warming bees, are workers that actively generate heat to keep the brood nest at an even temperature.
Heater bees, also called warming bees, are workers that actively generate heat to keep the brood nest at an even temperature. Instead of moving their wings, they tense the flight muscles in the thorax and let them vibrate against each other, so that heat is generated purely through muscle friction. For this, heater bees often position themselves directly on or between capped brood cells and pass their body heat directly on to the developing pupae.
The goal of this heating activity is a brood nest temperature in the range of about 32 to 36 degrees Celsius, whereby deviations over a longer period can visibly disturb brood development, risking malformations of the wings, legs or abdomen. Because the brood itself can barely generate its own heat, an even brood temperature depends entirely on the interplay of many heater bees in the colony, which distribute themselves across the brood nest as needed.
For practice, this behavior explains why small, bee-poor colonies have difficulty keeping larger brood areas warm in early spring, and why heavily thinning a colony in spring is risky. Good thermal insulation of the hive also supports the heater bees, because less energy is lost to balancing the temperature with the outside air. A common misconception is attributing temperature regulation solely to the queen or to the bee cluster as a whole; in reality, individual, specialized heater bees take on this task specifically.