Belugas may communicate by warping a blob of forehead fat

Whales in captivity can mold their “melon” into at least five different shapes

A beluga whale looks toward the camera, its forehead bulging out prominently

Beluga whales like this one at Connecticut’s Mystic Aquarium sport a blob of forehead fat called a “melon.” The cetaceans contort the melon into different shapes, possibly to communicate with each other.

Paul Souders/Getty Images

The beluga whale wears its heart on its sleeve — or rather, its forehead.