Sensitive Crocodiles

Photograph: David Grunfeld/Getty Images 

Crocodiles and alligators' snouts are more touch-sensitive than human fingertips, a new study shows. Alligators have 4,000 tiny, raised black spots on their heads, along their jaws, inside their mouths, and between their teeth. Crocodiles have about 9,000. Scientists have known about these bumps – called integumentary sensory organs – for more than 100 years, but until now their purpose was a mystery.