The whiskers have a big job of keeping the cat safe, as cats are nocturnal they use the whiskers to navigate themselves around in the dark and unfamiliar areas. The whiskers help the cat to navigate in the dark, the cat can also use the whiskers to pick up atmospheric changes and changes in wind direction.
Cats normally have 24 whiskers, twelve on each side of their face. Whiskers are thick hairs that are rooted into the skin, the root of the whisker is attached to a cluster of nerve endings. The whiskers are sensitive to air pressure and movements, these act like a radar to the cat. Any movements that are sensed by the whiskers give the impression to us that the cat can sense or see things that we cannot , ever seen a cat looking at something that is not there?
The cat uses the whiskers to judge space, using them to measure spaces of openings to see if he can fit through, the whiskers are sensitive to pressure leaving him sure if the width of the opening is suitable. The whiskers are usually around the same width as the cats body, so bigger cats will have bigger whiskers and petite cats will have smaller whiskers.
You can use the whiskers as an indication of the cats mood, if happy the cat will have relaxed open whiskers, if angry the whiskers will be pulled back and drawn into his face. Whiskers do fall out and will be replaced by regrowth, never cut your cats whiskers as this will impair your cats judgement and abilities. Cats also have thicker hairs over their eyes, on the side of their cheeks and on the back of their front legs, these all act like whiskers.