In slow-motion video, the buff-tailed bumblebee (Western bumblebee) exhibits unique, context-sensitive behaviors in response to sweet and bitter tastes, mirroring mammalian reactions of pleasure and aversion. This discovery adds new insights into the ongoing debate surrounding insect consciousness.
Zhou et al. demonstrate that the buff-tailed bumblebee (Western bumblebee) exhibits orofacial responses that reflect emotional evaluations rather than mere feeding reflexes. Image credit: Ralphs Fotos.
Professor Andrew Barron from Macquarie University stated, “This groundbreaking discovery alters the scientific understanding of the inner lives of insects.”
“Facial expressions serve as a crucial window into an animal’s internal state,” he added.
“There’s always been a tension between viewing insects as sentient beings and perceiving them as mere mini-robots.”
“This study is a vital step toward confirming that bees possess an inner life.”
For this research, Professor Barron and his team studied 18 colonies of buff-tailed bumblebees.
The researchers isolated individual bees in observation tubes and trained them to find tiny droplets of 20% sugar water positioned just beyond the reach of their antennae.
The bees quickly adapted, extending their mouthparts (proboscis) to access the droplets.
The team recorded the movements of the bees’ facial and mouthparts after ingesting various test droplets containing different concentrations of sugar water, plain water, salt water, or the bitter compound quinine.
The results revealed distinctly different orofacial behaviors after consuming sweet liquids compared to bitter and salty liquids.
The protrusion of the glossa (tongue) after tasting sugar solutions was analogous to “lip licking,” occurring immediately following sweet consumption.
This reaction paralleled human behaviors, such as shaking one’s head in disgust or wiping the mouth, after tasting salty or bitter substances.
“Many people comfortably assert that insects can sense, learn, and make decisions, but they are even more confident in stating that insects can evaluate experiences as pleasurable or unpleasant,” noted Professor Fei Peng, a researcher at Southern Medical University.
“Our findings validate that intuition.”
“While we are still uncertain about the actual experiences of bees, we can observe behaviors that closely resemble emotions,” Professor Barron explained.
“Importantly, we now have actionable insights into their inner lives that can be further explored.”
“The implications extend beyond bees to all insects,” he added.
“There are no significant differences between the brain structures of bees and flies, suggesting that ethical considerations in how we treat insects need to be revisited.”
“By human standards, the honey bee’s brain is small—less than a milligram—but our evidence indicates that this impressive brain can support a form of inner life in bees.”
“This study represents a significant step in understanding how brain activity correlates with subjective experience.”
“We hope that future research will illuminate how the mental lives of bees arise from neural mechanisms, helping to bridge the gap between mind and body.”
For more details, refer to the study published on July 6th in Proceedings of the National Academy of Sciences.
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Zhou Yonghe et al. 2026. Bumblebee orofacial responses to taste provide evidence for emotional appraisal. PNAS 123 (28): e2529114123; doi: 10.1073/pnas.2529114123
Source: www.sci.news
