Alligators have a number of special features that have allowed them to stick around for 180 million years.
In fact, alligator eyes have two sets of eyelids!
The outer lids are like human eyelids. They are made of skin and close top-to-bottom. The inner lids are clear and close back-to-front.
While an alligator is sitting about or swimming, these inner eyelids protect the alligator's eyes and provide clearer vision in the underwater environment.
When swimming underwater, alligators are water tight.
Flaps close off the ears and nostrils, the inner eyelids protect the eyes, and a special flap closes at the back of the throat, to keep water out of the throat, stomach and lungs.