While they can't pick out precise numbers, animals can comprehend that more is, well, more. From birds to bees and wolves to frogs, animals use numbers to hunt, find a mate, return to their home, and more. Researchers believe that this ability, known as numerical competence, plays an important role in how animals make these decisions. Andreas Nieder, a biologist at the University of Tübingen, explores the current literature on how different animals comprehend numbers.

Honeybees, for instance, can remember the number of landmarks they pass when searching for food in order to find their way back home. This ability can also be seen in animals choosing a larger amount of food over a smaller amount or in animals forming hunting groups. Wolves are more likely to hunt successfully if they have the right number of wolves in their pack for their prey (猎物) with prey like elk (驼鹿), only around six to eight wolves are needed, while hunting wild pigs requires a pack of nine to thirteen. Their prey also uses this concept to protect themselves—elk tend to live in small groups, which rarely have encounters with wolves, or gather in large groups to reduce the chance of any individual becoming prey. "They are assessing the number of individuals in their groups for their everyday life situations," Nieder says.

Furthermore, numerical competence also plays a role in attracting a mate. For example, male frogs sing "advertisement" calls to attract females. The females, listening to their complicated calls, choose the males that sing the most "chucks" in their calls.

Now researchers do have some sense of the rules that govern numerical competence in animals. For example, they count approximately (大概) rather than specifically and two numbers need to be more different for them to tell them apart as those numbers get bigger. However, Nieder argues that more research needs to be done. "I hope I can encourage behavioral ecologists to specifically explore numerical competence in the wild, and, in doing so, also open new research fields," he says.