Bees order numbers in increasing size from left to right, a study has revealed, supporting the theory that this direction is inherent in all animals including humans.
Western research has found that before children learn to count, they start organising growing quantities from left to right in what has been called the "mental number line".
However, the opposite direction has been found in people from cultures that use an Arabic script which reads from right to left.
"The subject is still being debated between those who think the mental number line has an innate character and those who say it is cultural," said Martin Giurfa, a professor at the Research Centre on Animal Cognition at Paul Sabatier University in Toulouse, France.
There has been recent evidence that newborn babies and some vertebrate animals, including primates, organise numbers from left to right.
Giurfa led a study, published last week in the journal Proceedings of the National Academy of Sciences (PNAS), aiming to find out if the same holds true for insects, via an experiment on bees.
"It has already been shown that bees are able to count – at least up to five," Giurfa told AFP.
They also process information differently in the two hemispheres of their brains, he added.
This trait they seem to share with humans, and is thought to be a potential reason for the existence of the mental number line, Giurfa said.
Left or right?
For the experiment, the researchers had individual honeybees fly into the first of two compartments of a wooden box.
They then removed the sugar-water reward and observed which way the bees went.
Read more on RFI
Scientists in Morocco use fake nests to entice flamingos to breed
South American invasive stinging ant spotted in France for first time
Humans have wiped out two-thirds of world's wildlife since 1970