India, May 22 -- A crow doesn't need a compass or a protractor to know when something looks off. That's the latest revelation from a study in Science Advances, which shows that carrion crows can spot geometric regularity- symmetry, parallel lines, and right angles. Two birds, no math class, and yet they could tell when a shape wasn't spot on.

We humans have long considered geometric intuition our exclusive domain. The ability to recognise when shapes follow orderly principles and to instinctively grasp concepts like symmetry and perpendicularity has been described as a unique human talent. Geometry is a way of thinking found across cultures, even in people with no formal education. This basic sense of shape regularity underpins centuries...