New research indicates that bumblebees may exhibit behavior suggestive of emotional responses to taste, challenging long-held assumptions about insect cognition. Experiments reveal that after consuming sugary substances, bumblebees display a repeated tongue movement reminiscent of lip-licking in humans, while tasting bitter or salty liquids prompts head shaking and mouth wiping gestures.

The study, published in the Proceedings of the National Academy of Sciences, sought to determine whether these orofacial behaviors reflect mere reflexes tied to food safety or calorie content, or if they indicate a more complex evaluation of taste. Researchers observed bumblebees from 18 colonies of Bombus terrestris after offering them sweet, bitter, and salty solutions and recorded their responses using slow-motion video.

The bees consistently extended their glossa—the insect equivalent of a tongue—in a deliberate manner following sugar intake, a behavior interpreted as an expression of satisfaction. Conversely, exposure to bitter or salty tastes resulted in movements akin to attempts to remove unpleasant substances, such as head shaking and mouth wiping.

Lead authors Fei Peng and Cwyn Solvi at Southern Medical University in Guangzhou argue that these gestures are indicative of “affective evaluation,” suggesting that bees might experience sensations resembling pleasantness or unpleasantness, rather than simply reacting by reflex. Andreas Barron, a professor at Macquarie University in Sydney and co-author of the study, noted that facial expressions are commonly used to infer internal states in animals, and their findings imply a more nuanced “inner life” in bees.

Barron highlighted the similarities in brain organization between bees and flies, emphasizing that despite the bee’s brain weighing less than a milligram, it appears capable of supporting complex responses. The implications of these findings extend to broader questions regarding insect sentience and how humans understand and interact with these creatures.

The researchers contend that recognizing such behaviors in bees could reshape perspectives on insect cognition and welfare, challenging the traditional view of insects as mere automatons. Further studies may explore the extent to which insects possess subjective experiences, potentially opening new avenues in the study of animal consciousness.