Hens cluck to call their chicks. Howler monkeys roar to keep others from their territory. Bats squeak when flying in the dark. The sound waves of their squeals bounce off objects and echo to warn them that they may be close to flying into something.
Snakes have no ears, so sound vibrations are helpful.
They keep their head on the ground. Sound vibrations alert them that an enemy may be near. Mother whales find their baby by sending clicking sounds through the ocean. The mother can then hear when the sound waves echo off her baby.