FAQ #4: Why Do Cats Have Whiskers?
Whiskers are specialized sensory hairs equipped with touch receptors. Compared to the hairs that make up the fur coat, whiskers are longer, thicker and more rigid. These specialized hairs are also embedded more deeply into the cat’s body than the hairs of the fur coat. The area around each whisker, called a follicle, has a generous supply of nerves and blood vessels. This follicle is seated in a complicated network of fine muscles that provide voluntary movement for each whisker. It is important to note that while whiskers are referred to as “tactile hairs”, the whiskers themselves cannot feel anything. Instead objects that brush up against a whisker will cause it to vibrate, which then stimulates the nerves within the hair follicle. This is why the scientific name for whisker is vibrissae, derived from the Latin word, vibrio, meaning “to vibrate”.
Most cats have twelve whiskers that are arranged in four rows on each cheek. These vibrissae are connected to and communicate with the muscular and nervous systems, relaying information about the cat’s surroundings – sort of like “kitty radar”. They are particularly useful to animals that must navigate in dim light, namely nocturnal animals. Most mammals have these tactile hairs around the face, as well as other parts of the body. Cats, in particular, have tactile hairs over their eyes, under the jaw, and on the backs of their forelimbs just above their paws.
Cats have a sensory organ located at the end of each whisker called a proprioceptor, which sends tactile signals to the central nervous system. These proprioceptors make the cat’s whiskers very sensitive to even the slightest change in the cat’s environment. A cat’s whiskers not only help the cat determine if it can fit into a tight space, they can also respond to vibrations in the air and changes in air current, which can be helpful when the cat is chasing prey or navigating around barriers in the dark. Cats that are blind can use their whiskers to adapt very quickly to the landscape of the space around them, enabling them to navigate their surroundings safely even without vision. Whiskers can also serve as a way to enable cats to visually measure distance, which is why they are able to leap so quickly and gracefully onto narrow landings. The whiskers located on the back of a cats forelimbs serve to help them climb trees.
Whiskers can also serve as a sort of barometer for a cat’s moods. The way a cat arranges them will tell other animals, or humans, how it’s feeling. When a cat is resting or content, its whiskers will be mostly immobile and sticking straight out from the sides of the face. However, if the whiskers are suddenly drawn together flat against the cat’s face, that is most likely a signs that the cat is frightened or angry. When playing or hunting, the whiskers will be drawn forward and sometimes appear to almost wrap around the prey.
Over time, cats and their ancestors developed genetic programs to ensure the length of the facial whiskers would grow to be proportionate to the size of the head. Contrary to popular belief, whisker length does not correlate to body size. If a cat is obese, their whiskers will not grow to a width that parallels the size of their body. Certain breeds of cat have interesting features to their whiskers. For instance, the Devon Rex typically has curly whiskers, while the Sphinx often has little to no whiskers at all.
While it is an old wives’ tale that cutting a cat’s whiskers off will affect the cat’s balance, it can compromise their ability to “feel” around their face. So while it is not painful for a cat to have their whiskers cut, it is certainly not ideal. If whiskers are cut, and the follicle is not irritated, they will be replaced, but not until the animal’s next shed cycle comes around. Cats occasionally will shed their own whiskers, but typically only one or two at a time.
-Dr Christie Taylor, The Pet Hospitals