A honeybee takes nectar from a flower as pollen grains stick to its body in Tanzania (Photo Credit: By Sajjad Fazel – CC BY-SA 3.0 from Wikimedia Commons )

Just a few decades ago, humans were the only species believed to be smart enough to grasp the concept of zero — the idea that nothing can be counted as something. While a select group of animals, including dolphins, primates, and a few birds, have since been added to the list, experts have always maintained that only “intelligent” species are capable of processing the difficult concept. Now, researchers from Melbourne’s RMIT University and France’s Université de Toulouse assert that honeybees, which like all insects are considered to be at the low end of the cognitive spectrum, also understand the abstract mathematical notion of nothing.

Credit: RMIT University

Given that bees have about one million brain neurons — compared to the 100 billion in the human brain — the idea to put them up to the challenge may appear odd. However, the team of bio-cognition researchers led by Scarlett Howard, a Ph.D. candidate, at RMIT University had a hunch that the humble insect may be one of the few species able to grasp the concept.

“My lab was starting to accumulate some evidence that bees could do some advanced cognitive tasks, such as tool use, playing ‘soccer’—manipulating a ball to get a reward—and learning to encode information in human faces,” says RMIT University associate professor Adrian Dyer, who co-authored the study published in the journal Science on June 8, 2018. “We were aware that this animal model was very capable of learning complex things … it was the right time to formalize an experiment to see if the bee brain could process the concept of zero.”

To teach the two test groups of 10 bees each the arithmetic concepts of “less than” and “greater than,” the scientists created white panels featuring a varying number of black dots. One group was rewarded with sucrose water when they flew to the panel with the larger number of circles, while the second batch received the treat when they gravitated towards the one with fewer markings. Soon, with enough practice, the bees continued choosing the right panels even when a sweet liquid reward was not awaiting them.

Credit: RMIT University

The next step was to present the bees with a previously unseen stimulus – a blank sheet, which in this case represented “zero.” Alongside it was a sheet containing the familiar black circles. Sure enough, the bees trained to recognize “less than” flocked to the blank sheet, while those trained to seek out the higher number chose the one with the circles. The scientists observed that while the bees were able to differentiate between zero and one, they performed better when presented with panels that had numbers further apart, such as zero and five. According to Dyer, the results are consistent with those of similar studies conducted on young children. The scientist believes the correlation in the bees’ and humans’ development of zero processing capability indicates that both conceptualize the number in analogous, or comparable, ways.

Not everyone is convinced by the study’s conclusions. Clint Perry, a research fellow at the Queen Mary University of London, who has spent many years studying bee cognition, believes more research is required to determine if the insects can truly grasp the concept of zero. The expert says, “The more parsimonious [simplest] explanation for the results is the bees were using ‘reward history’ to solve the task—that is, how often each type of stimulus was rewarded. It’s possible the “less-than” bees, for example, were truly just learning that the blank panel earned them a reward 100 percent of the time, the one-shape panel 80 percent of the time, and so on. In other words, they were simply playing the best odds they could with the panels they were shown, without necessarily understanding the concept.”

Bee gravitating to the “zero” sheet (Credit: RMIT University)

However, Dyer is confident that the findings, though based on a small sample of bees, are accurate. He says, “This study produced high-quality behavioral data, and from that, you can make some inferences. But we don’t know the exact neural networks at play—that is future work we hope to do.” The associate professor believes understanding the mechanics of the brains of animals, such as bees, could be helpful in the development of artificial intelligence.

Resources: Smithsonianmag.com,popularmechanics.com, theconversation.com