Bumblebees shake their heads if they do not like food

Bumblebees shake their heads if they do not like their food, researchers have found.

Slow-motion video has captured the insects moving their heads quickly from side to side and wiping their mouths if they dislike certain liquids.

They have also been recorded licking their lips when they like what they are consuming.

A study of 18 colonies of bumblebees was carried out by Professors Fei Peng and Cwyn Solvi, of Southern Medical University in Guangzhou, China.

It found that the insects demonstrated “liking and disliking” behaviours, as opposed to “wanting” actions or feeding reflexes.

Prof Peng said: “Many people are comfortable saying that insects can sense, learn, and make decisions, but much less comfortable saying that they may evaluate things as pleasant or unpleasant.

“Our findings push on that intuition.”

The groundbreaking study, published in the journal Proceedings of the National Academy of Sciences (PNAS), produced key findings including bees displaying “distinctly different” facial behaviours after consuming sweet liquids compared to bitter and salty liquids.

The researchers observed post-consumption glossa – or “tongue” – protrusions, akin to the bees licking their lips after eating sugar solutions.

Aversive head shaking and mouth wiping was also recorded after the insects tasted salty and bitter liquids.

Such emotive responses have never previously been observed outside of mammals, and raise questions about our understanding of the consciousness of all species of insects, say scientists.

Professor Andrew Barron, from Macquarie University in Sydney, Australia, said the revelations change the scientific understanding of the inner life of insects.

He said: “Facial expressions are an important window into the internal states of animals.

“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.”

Bees appear to be showing emotion

Prof Barron, a neuroethologist who studies the connections between animal behaviour and its nervous system, added: “We don’t yet understand what the bees truly experience, but we can observe emotion-like behaviours.

“What’s important is we’ve now got a practical read on their inner life that we can work with experimentally.”

Prof. Barron says the findings could have far-reaching implications beyond bees and offer a greater understanding of other species of insects.

“In terms of how the brain is organised, there’s no major difference between a bee and a fly,” he said. “This means there’s more to consider in terms of how we might treat or react to insects.

“By human standards, the bee brain is tiny – weighing less than a milligram – and yet our evidence suggests the remarkable bee brain can support a form of bee inner life.”  

Prof. Barron says the research also points towards a greater understanding how brain activity relates to subjective experience.

“We hope further studies will show how the bee’s mental life arises from mechanisms in the brain so we can close the gap between the mental and the physical,” he said.

[Source: Daily Telegraph]