The study raises the question of how a species that differs so much from humans - with fewer than one million neurons in its brain, compared to a human's 86,000 million neurons - can share such a complex skill. Howard placed sugar water under the card that contained the least amount of symbols and, eventually, the bees understood the concept of greater or lesser as they flew each time to the card with the least number of symbols.
The number zero is the backbone of modern maths and technological advancements, according to Adrian Dyer, associate professor from the Royal Melbourne Institute of Technology (RMIT). For long, it was believed that humans were the only ones to get the concept, but the recent work has changed the notion. Even several ancient human civilisations lacked the understanding of zero, a concept that is thought to have originated in India around the 5th century.
Bees could be smarter than us in the understanding of "zero".
The fact that the bees went to the blank image shows that bees understood that nothing was lower than the other quantities shown, and the researchers say this provides a new understanding of how different brains grasp abstract concepts.
RMIT PhD researcher Scarlett Howard set out to test the honeybee on its understanding, marking individual honeybees for easy identification and luring them to a specially-designed testing apparatus.
For example, the bees learned to choose three elements when presented with three vs. four; or two elements when presented with two vs. three.
They managed to understand that zero was less than one, despite never having been exposed to an "empty set".
"This is a tricky neuroscience problem", he said.
Neurons can easily respond to light and other stimuli, but the ability to represent nothing as zero indicates that some animals and insects may have evolved special neural mechanisms to perform the task.
"Crossing a road is simple for adult humans, we understand if there are no approaching cars, no bikes or trams, then it is probably ok to cross", he said. New findings suggest that untrained honey bees have the intellectual capacity to understand the concept that zero has value.
The number zero has an integral role in mathematics and many algebraic structures.
"If bees can perceive zero with a brain of less than a million neurons, it suggests there are simple efficient ways to teach artificial intelligence new tricks", said Mr. Dyer.
A research team comprised of scientists in France and Australia were interested to learn what else, if anything, the insects could do, mathematically speaking. "So it's not the same category", Aurore Avargues-Weber, a CNRS researcher with the University of Toulouse, told NPR.