No dumb clucks, young chickens appear capable of basic arithmetic, Discover reports. Scientists relied on two innate chick traits—an instinct to flock with the biggest group and an attachment to objects—to test the birds’ noggins. After hiding yellow balls of varying numbers behind screens, they released the chicks. The birds went immediately to the screen with the most balls.
The findings held true even when balls were moved around after the screens were in place, requiring the chicks to add and subtract. “Numerical understanding comprises a built-in system of unlearned knowledge,” a scientist concludes. Besides humans, chickens are the only other animals known to demonstrate numerical abilities in their youth. Primates and dogs gain such skills as adults.