You have probably heard a dog start barking when someone comes close to their house. Red squirrels will make a series of rattles, screeches and yips to warn off intruders. The bottlenose dolphin has a wide range of vocalizations. Some scientists think they have a language and are working to see if humans can communicate with dolphins. Each dolphin also has its own unique whistling sound that it uses to identify itself.
Dolphins use sound or echolocation to locate food.
They have sacs in their foreheads that they use to make clicking sounds. The sounds travel through the water and when they hit something, bounce back to the dolphin.