फ्री वीडियो देखें The Science Behind Porpoises’ Echolocation

Some animals use additional senses to see the world differently than humans. One such sense is called biological sonar. Biological sonar is when an animal releases a series of sounds that may not be audible to humans and waits for the echoes to return. Toothed whales, which includes porpoises, are one of two types of animals that use biological sonar to sense and navigate through their environment (the other being bats).