It can be hard for animals to see in murky waters. Dolphins, like this bottlenose dolphin, can’t depend on vision when they swim around and hunt for food. But sound waves travel well in water—and dolphins use that to their advantage.
A dolphin’s ears can sense the size, shape, and distance of the objects around it, using an ability called echolocation. To scan its surroundings, a dolphin first makes loud clicking sounds. The sound waves bounce off rocks, sand, and prey animals and return to the dolphin’s ears. The shape of a dolphin’s jaw helps guide the vibrations to the inner ear. The dolphin’s brain then determines what each object is and about how far away it is.
According to marine biologist Aran Mooney, dolphins can use their ears to tell two types of fish apart from 100 meters (330 feet) away!