The third eyelid is called a nictitating membrane or haw. This third eyelid keeps moisture in and debris out. It is a sort of windshield-wiper that keeps the eye clear and healthy. The third eyelid is really only visible if our dog suddenly open his eyes, like when they are startled awake or when they are first opening their eyes after a long, deep sleep.
- Cats have over one hundred vocal sounds, while dogs have about ten!
- Cat whiskers are so sensitive they can detect the slightest change in air current.