Overview
- The PNAS study, published Monday, used high‑frame‑rate video of Bombus terrestris to show repeated glossa protrusions after sweet solutions and head‑shaking and mouth‑wiping after salty or bitter solutions.
- Researchers found the tongue‑protrusion response rose with sugar concentration and shifted with internal state, for example when heat‑dehydrated bees treated salty water as desirable.
- Pharmacological tests dissociated motivation from enjoyment: dopamine raised food‑seeking drive without increasing glossa protrusions while endocannabinoid treatment boosted tongue‑protrusion rates.
- Independent experts say the work provides strong evidence of flexible value representation in bees but caution it does not prove human‑style pleasure and needs neural‑level validation.
- Beyond scientific debate, the findings could prompt new studies mapping bee brain activity and renewed discussion about how moral and practical policies treat insects.