Mathematics is certainly one of the most striking examples of the cognitive divide between humans and other animals. What could be more abstract than manipulating mathematical symbols? Yet mathematical reasoning, although acquired through education and cultural transmission, nonetheless rests on a set of biologically based, preschool-level mathematical skills shared with, among others, non-human primates. Chimpanzees, for instance, can count and order small quantities, solve simple arithmetic problems involving addition and subtraction, and associate symbols such as Arabic numerals with quantities. These abilities could therefore be regarded as the biological roots of our mathematics.
Given the strong adaptive value of an ability to count in situations as varied as choosing a quantity of food, assessing the balance of power between social groups by their size, or helping with orientation in the environment or object recognition, it is perhaps not surprising to find this ability in many vertebrate species, from fish to mammals to birds. Only reptiles appear to lack it. It is true that, relative to their body size, their brains are rather small, but researchers must admit that it is not easy to motivate a snake or a crocodile to display its intellectual abilities! Learning that even insects can assess quantities may come as more of a surprise, if only because of their miniature brains (yes, insects really do have a brain!), but also, of course, because of their evolutionary distance from humans. Yet certain ant species can count their steps to gauge distances or rely on a number of visual landmarks; they also become more aggressive in conflicts when they belong to a larger group. Mealworms are drawn to a substrate carrying the scent of a greater number of females, bumblebees can gauge the level of competition from the number of other bumblebees visiting a food source, and crickets flee more readily toward an area offering the greatest number of potential shelters. Beyond insects, spiders are also able to remember the number of prey caught in their web, and cuttlefish choose to hunt the shoal containing the greatest number of shrimp.
The value of studying bees
But are these examples really evidence of a "sense of number" — that is, the ability to recognize a precise quantity of objects independently of other physical parameters linked to quantity, such as density, cumulative surface area, or motion? Verifying the existence of a genuine, abstract sense of number, like our own, requires controlled experimental procedures. Bees' abilities have accordingly been studied extensively in recent years. Why bees? For three main reasons.
First, bees' foraging behavior requires strong learning abilities, making them an ideal model for studying all forms of intelligence. Bees must be able to learn which flowers are worthwhile among all the available options, remember where to find them and at what time of day they yield nectar, and navigate their surroundings — since finding the hive, often several kilometers from the flowers they exploit, is like finding a needle in a haystack!
