Tongue microstructure physically constrains division of labor in bumblebee foraging

Proceedings of the National Academy of Sciences, Volume 123, Number 3, January 2026.
The bumblebee (Bombus terrestris) is a primitively eusocial species that supports its colonies by dividing foraging tasks between queens and workers. Previous research emphasizes hormonal, metabolic, and behavioral contrasts between castes, but rarely…