Bees are probably the first invertebrate animals to understand the idea of zero in terms of absence of quantity , or at least that seems to be deduced from research carried out by Scarlett Howard of the Royal Melbourne Institute of Technology (RMIT) in the Australian University of Melbourne. When the scientists involved in the experiment encouraged insects to fly towards a platform that contained fewer shapes than another , they apparently recognized the notion of “no shape” as a lower quantitative value than “some shapes.” The study was presented by Scarlett Howard herself at a recent conference on animal behavior in Estoril, Portugal, and has been published in New Scientist magazine.
The idea of zero is difficult to understand even for human beings . In fact, young children often have a hard time assimilating it and usually learn what zero is after having learned other numbers. In the animal kingdom the understanding of this concept is not frequent either. Practically only chimpanzees and some other monkeys, if they are taught and trained to do so, can learn it . So it is surprising that bees, which have a very small brain, can also do it, which is beyond the ability of other invertebrates.
To test whether these insects were able to understand zero, Scarlett Howard and her colleagues previously trained bees to differentiate between two numbers or quantities . With that objective, as they explain, they built two platforms. In each of them there were between one and four different shapes. In one platform, the bees were given a sucrose solution, sweet and attractive to their palate, and in the other an unpleasant-tasting quinine solution . Previous research had shown that these insects learn more quickly if they are not only rewarded for the right choices, but also when they are punished for the wrong choices .
On this occasion, the scientists trained the bees to associate the platform with the fewest shapes on it with the sweet reward. They did it enough times to make the right choice 80% of the time. The bees were then subjected to further tests with objects of different shapes to confirm that they responded to the number of shapes and not their appearance. Next, when given a choice between two or three shapes and “zero” shapes, the bees chose zero most of the time .
In a second experiment, other bees were trained in the same way, but this time they had to choose between landing on a platform with zero, one and six objects. The insects always chose “zero”, but they were less precise and took longer when the other option was one instead of six objects.
For the scientists, the fact that the numerical distance between the two quantities offered seemed to affect the difficulty of deciding is further proof that they probably conceive of zero as a number or quantity . However, Scarlett Howard is still not clear why they have this ability: “We still need to carry out more research to find out why they are capable of doing this.”
