As a mathematical concept, the idea of zero is relatively new in human society—and indisputably revolutionary. It’s allowed humans to develop algebra, calculus and Cartesian coordinates; questions about its properties continue to incite mathematical debate today. So it may sound unlikely that bees—complex and community-based insects to be sure, but insects nonetheless—seem to have mastered their own numerical concept of nothingness.
Despite their sesame-seed-sized brains, honey bees have proven themselves the prodigies of the insect world. Researcher has found that they can count up to about four, distinguish abstract patterns, and communicate locations with other bees. Now, Australian scientists have found what may be their most impressive cognitive ability yet: “zero processing,” or the ability to conceptualize nothingness as a numerical value that can be compared with more tangible quantities like one and two.
While seemingly intuitive, the ability to understand zero is actually quite rare across species—and unheard of in invertebrates. In a press release, the authors of a paper published June 8 in the journal Science called species with this ability an “elite club” that consists of species we generally consider quite intelligent, including primates, dolphins and parrots. Even humans haven’t always been in that club: The concept of zero first appeared in India around 458 A.D, and didn’t enter the West until 1200, when Italian mathematician Fibonacci brought it and a host of other Arabic numerals over with him.
But animal cognition researchers at the RMIT University of Melbourne, Monash University in Clayton, Australia and Toulouse University in France had a hunch that honey bees might just be one of the few species able to grasp the concept. Despite the fact that they have fewer than one million neurons in their brain—compared to 86,000 million in a human brain—the team recognized their cognitive potential.
“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 Adrian Dyer, a postdoctoral student at RMIT University of Melbourne and co-author on the study. “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 test this hypothesis, the team first taught the bees the concepts of “greater than” and “less than,” which previous research suggested the bees would be able to do. The researchers figured that if the bees could successfully show they understood that zero was less than various positive numbers, this would demonstrate the insects’ understanding of zero’s numerical value.
To do this, they first lured two groups of 10 bees each to a wall where two white panels containing different numbers of black shapes were displayed. They decided to teach half the bees “less than” and the other half “greater than,” using food rewards to train the bees to fly toward the panel with fewer or