Bees seem to be the first invertebrate to understand the concept of zero, thus joining a small group of species which are capable of comprehending the idea, according to a recent study conducted by Scarlett Howard and her colleagues at RMIT University in Melbourne.
Before this important discovery, humans and their close relatives primates and monkeys, were the only living creatures known to consider zero as a quantity, a very complex capability usually requiring a large brain. However, finding that bees with their tiny brains are able to grasp the notion of zero really startled the scientists, but this is not the first time that these insects exhibit highly-developed numerical skills, since previous studies have shown that these honey-producing animals can count to four.
The breakthrough was a result of a series of experiments in which bees were presented with two platforms, each with between one and four shapes on it. The goal of the test was to teach bees to distinguish larger from smaller numbers by picking a platform with fewer shapes on it. That was achieved by placing a sweet solution on the platform with fewer shapes in order to attract the bees, while putting a bitter solution on the platform with a higher number of shapes to repel the insects. After a while, bees learned to pick a platform with fewer shapes 80% of the time. In the next stage of the experiment, bees had to make a choice between a platform with up to six shapes or a platform with no shapes on it. In most cases, bees picked the empty platform, thus showing they consider zero as less than one. However, it was easier for bees to pick an empty platform if on the other side there was a platform with a larger number of shapes. In other words, bees were less accurate when presented with a choice between one and zero compared to a choice between none or six.
Still, it’s not clear yet as to why bees have this ability or if it has any evolutionary purpose for them. “We still have some things to figure out about why they can do this,” said Scarlett Howard, author of the study.