Whiskers are long, thick hairs (2x to 3x the circumference of a normal hair) found in a large clumping of horizontal rows on both sides cat's face. They average 12 per side of the nose in the cat's "cheek" area known as the whisker pad. They can also be found on the chin, ears and eyebrows. Known as "tactile hairs" or feelers, whiskers are attached to large nerve bundles under the skin. Used mainly to navigate, a cat's longest whiskers tend to be as wide as their body. This helps mainly in judging whether or not a cat can fit through an opening (which is why you may se a cat poke just its head through any particular opening). Whiskers can pick up and translate a sensation of touch, such as if a cat touches its whiskers to an object. They are extremely sensitive and capable of picking even the slightest air current.

Whiskers can also communicate mood via facial expressions. Just like a dog, if a cat is disturbed or scared, it can pull back the corners of it's mouth and growl (yes, cats can growl). The whisker pad will also be pulled back and the whiskers will lay flat against a cat's face. Normally a cat's whiskers tend to be outstretched and relaxed.

Like hair and nails, whiskers grow, die and then fall out and are replaced by other whiskers. Even though the whiskers themselves are dead follicles when pushed outside of the skin, you should never trim a cat's whiskers as it can cause them to become unbalanced and disoriented. Seeing an excess of whiskers fall out is usually an indication that your cat is losing weight which can be a sign of illness.