Honeybees Understand the Complex Mathematical Concept of Zero

Honeybees are able to understand the mathematical concept of zero, according to a new study published in the journal Science. This places them in an elite group of animals that are known to be able to comprehend the abstract idea of "nothingnesss."

While it may seem obvious to us today, zero is actually an advanced numerical concept that many ancient human civilizations had difficulty grasping.

This makes it all the more remarkable that a tiny insect with a brain consisting of fewer than one million neurons—in comparison to the 86,000 million in the human brain—is capable of such a skill.

Recent research has shown how a few select animals, such as dolphins, primates and some birds, can understand zero. Now, a group of scientists from RMIT University in Melbourne, Australia, and the University of Toulouse, France, have shown that honeybees can also be added to this elite club.

"Zero is a difficult concept to understand and a mathematical skill that doesn't come easily—it takes children a few years to learn," Adrian Dyer, from RMIT, said in a statement. "We've long believed only humans had the intelligence to get the concept, but recent research has shown monkeys and birds have the brains for it as well. What we haven't known—until now—is whether insects can also understand zero."

Bees are an excellent model for understanding insect cognition, as previous research has shown that they can learn complex skills from other bees and are also capable of understanding abstract concepts like sameness and difference.

For the study, the researchers marked individual honeybees to identify them and lured them into a specially designed experimental area in which there was a wall containing white squares, each with a different number of black shapes on them (ranging from two to five).

The insects were trained using food rewards to select the white square (by flying towards it) with the lowest number of black squares. For example, the bees might choose a white square with three black shapes over one that had four white shapes.

The researchers then periodically introduced a choice the bees had not encountered in their training—a square with one black shape versus one with zero black shapes. They found that the bees were consistently able to distinguish no black shapes as lower than one, despite having never been exposed to an "empty" set before.

Dyer thinks that the findings could lead to a new understanding of how different animal brains represent zero.

"This is a tricky neuroscience problem," he said. "It is relatively easy for neurons to respond to stimuli such as light or the presence of an object, but how do we, or even an insect, understand what nothing is?"

Trained to pick the lowest number out of a series of options, a honeybee chooses a blank image, revealing an understanding of the concept of zero. RMIT University

"How does a brain represent nothing? Could bees and other animals that collect lots of food items have evolved special neural mechanisms to enable the perception of zero?" he added. "If bees can learn such a seemingly advanced math skill that we don't even find in some ancient human cultures, perhaps this opens the door to considering the mechanism that allows animals and ourselves to understand the concept of nothing."

According to Dyer, the study could also have implications for the development of artificial intelligence—a field in which one of the major challenges is enabling robots to operate in complex environments.

"If bees can perceive zero with a brain of less than a million neurons, it suggests there are simple efficient ways to teach AI new tricks," he said.