I was combing Kirk, my youngest cat, today and as I gently combed his head he twitched his whiskers.

Running the comb over his forehead, those whiskers twitched. Over each side of his head created the same reaction. Kirk didn't act like he was disturbed by the combing, but I also kept the grooming on his face to a minimum as I don't want him to dislike the process. However, his reaction reminded me how special and sensitive these special hairs can be.

The Whiskers Are Vibrissae

Whiskers are hairs, but not the same as the hairs in your dog or cat's coat. These stiffer, thicker hairs are called vibrissae and their follicles are embedded deeper in the skin than coat hairs. Although the whiskers are different from the hair coat, they are shed as the hair coat is and will grow back. It's often been said that animals can feel with their whiskers and that's not completely true. The whiskers themselves don't feel anything. However, when a whisker touches something and the whisker moves, the nerves in those deep hair follicles react to that touch. That's where the name vibrissae comes from; the Latin word vibrio which means to vibrate. You can see how this works by touching just one of your dog or cat's whiskers. She may move that whisker away from your finger or pull her face away from your hand. It's not painful but repeated touches may well be annoying because of the reaction of the nerve to the movement. Many animals have vibrissae type whiskers, including dogs, cats, ferrets, rats, horses, and even seals.

Where Are Whiskers Found?

Cats generally have four rows of whiskers on each side of the muzzle; often with twelve whiskers on each side. Tabby cats often have a dark spot in the hair coat to mark the root of each whisker. Cats of other colors may or may not have this spot. Many cats will also have whiskers above the eyes and sometimes even one or two under the chin. If you gently run your fingers over the hair on the back of your cat's front legs, you may feel some stiffer hairs there, too. Not all cats appear to have whiskers there, though. In checking my three cats, one had vibrissae on his legs and two did not. The whiskers on dogs are more variable than cats. My oldest dog, Bashir, an Australian Shepherd, has the same four rows of whiskers on each side of his muzzle that cats have, but he has considerably more whiskers under his chin. He has no whiskers above his eyes but my youngest dog, Bones, an English Shepherd, has several whiskers above each eye. A friend's Jack Russel Terrier has quite a few shorter whiskers on the sides of his muzzle and a few on his chin but none above his eyes. He does, though, have several on his cheeks. It's interesting that even hairless breeds of dogs and cats usually still have whiskers. They may not have hair coat but they do tend to have a normal complement of whiskers.

The Whiskers are Useful

The overall purpose of whiskers is not looks but instead, they provide additional information for the animal's senses. They can serve as antennae in low light situations, helping the animal move and not run into walls or obstacles. Even air currents can be felt by the whiskers. It's long been thought that the whiskers can help an animal judge as to whether he can fit into a small opening. Mice and rats, in particular, seem to use the whiskers on their muzzle to judge a small opening. Cats, too, will put their head into an opening but if the ends of their whiskers touch the sides of the opening, they then back out. That opening is too small. The whiskers on the face also work as antennae to protect the face. For example, if something touches the whiskers on one side of the animal's face, he will turn away, blink, or close that eye. For hunting animals or prey animals, the whiskers can communicate as to whether a predator or prey animal is too close or moving quickly; primarily, again by sensing air currents created by the moving animal. Grazing animals, such as horses, who can have many whiskers on the muzzle, can find food when the whiskers touch it. Since horses cannot see immediately in front of their muzzle, this is an important purpose of the whiskers.

Whiskers Convey Emotions

Whiskers are not generally one of the body parts people look at when gauging an animal's emotions, but they can actually tell you a lot. A dog or cat at rest will have his whiskers in a relaxed neutral position. When afraid, the whiskers tend to sweep back, sometimes to the point of being close to the cheeks. When angry, hunting, or alert, the whiskers will stand out or sweep forward. Although the whiskers on the muzzle are the most mobile, those on the cheeks and above the eyes move also. The ones on the chin move very little.

Don't Trim Them

Often groomers will trim a dog's whiskers so that the dog's face appears clean and neat. Dogs and horses competing in conformation dog shows usually have the whiskers trimmed, too. It doesn't hurt when you trim the whiskers; there are no nerves in the hair itself. However, they are an important part of your pet's senses so if at all possible, don't trim the whiskers.