Figure 3. Thermal infrared images of Trigona carbonaria bees immediately after participating in one of four activities:

Rest  =  not flying for at least 5 min, Fly  =  flying, Drink (amb)  =  imbibing sucrose from ambient feeder, and Drink (warm)  =  imbibing from warm feeder. Measurements were made with independent bees from the same colony considering three different ambient temperatures (23°C, top row; 30°C, middle row; or 34°C, bottom row). The body temperature of bees that were either resting or drinking from an ambient feeder were close to ambient temperature for all three tested ambient temperatures. However, whilst at the two lower ambient temperatures flying bees were hotter than the ambient temperature, at an ambient temperature of 34°C flying bees were close to the ambient temperature. All bees drinking from a feeder that was warmer than ambient showed a body temperature that was higher than ambient, and for an ambient temperature of 34°C this leads to a bee having a temperature that is well above the temperature bees attain during flight. Temperature scale shows temperature of bee relative to the background ambient temperature. Arrows show bee position in frame, and bee temperatures that are different from ambient are marked separately.