Executive Summary
- Honey bees must maintain a thorax temperature of at least 77°F to achieve flight, which is challenging in cold ambient temperatures.
- Research reveals bees use a “shivering” mechanism, activating their flight muscles while stationary to heat their thoraxes to over 95°F.
- This ability allows bees to perform critical tasks like water collection in temperatures near 40°F, but it carries a high risk of death if they cannot sustain the heat for their return flight.
Scientific research has detailed the physiological mechanisms that allow honey bees to conduct flights in air temperatures as low as 39°F, a feat previously thought to be highly improbable. Studies show that bees generate significant internal heat through a process similar to shivering, enabling them to maintain the required muscle temperature for essential tasks like collecting water even during cold weather.
According to entomological research, including a 1993 study by Bernd Heinrich, worker bees must maintain a thorax temperature of at least 77°F to power their flight muscles. Given that a bee can typically only keep its thorax about 27°F warmer than the ambient air during sustained flight, foraging below 50°F has long been considered a rarity.
However, a 2017 experiment conducted by Cornell University professor Tom Seeley and Ann Chilcott documented honey bees actively collecting water in temperatures as low as 39.2°F. This observation prompted further investigation into how the insects could overcome such a significant thermal challenge for short-distance flights.
A 2010 study utilizing infrared cameras provided a key insight into this behavior. Researchers found that while bees are stationary, such as when drinking water, they actively engage their flight muscles without moving their wings. This “shivering” mechanism preheats their thorax to temperatures consistently above 95°F, effectively preparing their muscles for the brief, critical flight back to the hive.
This ability, however, is not without risk. While the mechanism is essential for survival and hive maintenance, individual bees that venture out risk their muscles locking up if their internal temperature drops too quickly. This phenomenon explains why many bees are often found deceased in the snow after brief winter thaws, having failed to generate enough heat to complete their return journey.