What's the difference between dolphin clicks and whistles?
Unlike humans, dolphins don't make sounds through their mouths and they don't have vocal chords in their throat.
Instead dolphins make sound in two main ways:
They can produce whistles through their blowhole on the top of their head or;
Dolphin use clicks as a type of sonar in order to 'see' without using their eyes, and also in hunting, using intense pulses of sound to stun fish.
Dolphins don't just make click and whistle sounds. They can also make a huge variety of noises that sound like quacks, trills, yells, grunts and squeaks, either using a very high wavelength frequency or very low sounds.
The sounds that dolphins make may not be as beautiful as the ones that hump-back and other whales make, but they are an important means of communication.