In news that will delight bumblebee rights activists and mildly unsettle anyone who's ever swatted one, scientists have discovered that bees have something resembling inner lives - or at least, they have opinions about what they just ate.

Researchers from Macquarie University and Southern Medical University in China captured slow-motion footage of bumblebees tasting various solutions and found that, much like a toddler presented with broccoli, they make faces. When given something sweet (60% sugar), the bees extended their tongues - technically called a glossa - and kept licking after finishing, almost like a lip-smack. When given quinine or salt, they shook their heads and wiped their mouths. The findings, published in the Proceedings of the National Academy of Sciences, suggest these behaviors are consistent with "liking" and "disliking" responses seen in mammals.

Lead author Prof Andrew Barron said the study revealed that bees have "subjective like or dislike of those solutions" and that "there is an inner life to the insect." To rule out mere chemical reflexes, the team tested 18 colonies under various conditions, including heat stress, fullness, and drug doses. Context mattered: heat-stressed bees suddenly found plain water or salty solutions appealing - essentially, the insect equivalent of craving Gatorade after a marathon.

Associate Prof Thomas White, an entomologist not involved in the study, noted that most insect research focuses on negative states like pain or fear. This study's focus on pleasure was refreshing. "The picture is increasingly pushing towards a view that insects ... have some simple capacity to feel the world, not just to assess it and detect it and process information but to actually have a point of view," he said. That challenges where humans draw the line on ethical treatment of animals.

Barron summed it up: "There's always been a tension between thinking of insects as animals, or some sort of mini robots. This is another step towards showing there's an inner life to being a bee."