The honeybee (Apis mellifera) has joined the ranks of dolphins, parrots, and primates, in demonstrating the ability to understand the concept of zero numerosity. The study appears in the journal Science.
While intuitive to modern humans, the full understanding of zero is an advanced numerical concept that’s challenging to grasp; several ancient human civilizations lacked the full understanding of zero in their numeric systems.
Recently, scientists have shown that some vertebrates can understand the concept, and now, RMIT University researcher Adrian Dyer and co-authors present evidence that honeybees are also part of this ‘elite club.’
“The number zero was the backbone of modern maths and technological advancements,” Dr. Dyer said.
“Zero is a difficult concept to understand and a mathematical skill that doesn’t come easily — it takes children a few years to learn.”
“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.”
The study authors set out to test the honeybee on its understanding, marking individual honeybees for easy identification and luring them to a specially-designed testing apparatus.
The bees were trained to choose an image with the lowest number of elements in order to receive a reward of sugar solution. For example, the bees learned to choose three elements when presented with three vs. four; or two elements when presented with two vs. three.
When the scientists periodically tested the bees with an image that contained no elements versus an image that had one or more, the bees understood that the set of zero was the lower number — despite never having been exposed to an ‘empty set.’
“The findings opened the door to new understandings of how different brains could represent zero,” Dr. Dyer said.
“This is a tricky neuroscience problem. 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?
“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?”
“If bees can learn such a seemingly advanced maths 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.”
“The discovery that bees can show such elaborated understanding of numbers was really surprising given their tiny brain,” said co-author Dr. Aurore Avarguès-Weber, from the University of Toulouse, France.
“Large brains are thus not necessary to play with numbers. This capacity is therefore probably shared by many other animals.”
Scarlett R. Howard et al. 2018. Numerical ordering of zero in honey bees. Science 360 (6393): 1124-1126; doi: 10.1126/science.aar4975