The whiskers of a cat are enlarged stiffened hairs more than twice the thickness of ordinary hairs, and are embedded three
times deeper. They are supplied with a great many nerve-endings which transmit information to the cat's brain about any contact
they make or changes in air pressure that may occur.
An average cat has 24 whiskers, 12 on each side of the nose, which are arranged in four horizontal rows. They will move forwards
when the cat is inquisitive, threatening, or testing something, also backwards when being defensive or avoiding something.
The two top rows can be moved independently of the bottom two, also the most strongest whiskers are in rows two and three.
The cat is predominantly a nocturnal hunter, and relies upon its whiskers to detect minute disturbances in the air-currents,
this allows them to respond to solid objects without having to touch them. In a split-second they can detect the body outline
of their prey and react accordingly. A cat with damaged whiskers cannot kill cleanly at night, it tends to misjudge its killing-bite,
thus plunging its teeth into the wrong part of the prey's body.
Cats generally have about a dozen whiskers in four rows on each upper lip, a few on each cheek, tufts over the eyes and bristles
on the chin. Whiskers may also be found on the cat's "elbows." The Sphynx (a nearly hairless breed) may have full length,
short, or no whiskers at all.
Whiskers (technically called vibrissae) can aid with navigation and sensation. Whiskers may detect very small shifts in air
currents, enabling a cat to know it is near obstructions without actually seeing them. The upper two rows of whiskers can
move independently from the lower two rows for even more precise measuring.
Vibrissae (singular: vibrissa) are hairs that grow around the nostrils or other parts of the face in many mammals, usually
specialized for tactile sensation. In addition to the facial area, they can also be found on the wrists of the forelegs of
cats. They are usually thicker and stiffer than other types of hair. The term is also used in reference to the stiff feathers
near the mouths of some birds.
Vibrissae consist of inert material and contain no nerves. What makes vibrissae different from other hairs is that they are
implanted in a special follicle sealed by a capsule of blood, called a blood sinus. Touching a vibrissa causes it to bend
and the blood in the sinus is pushed to one side or the other. The blood amplifies the movement and allows the nerves at the
base to detect extremely small sensations. In some mammals, the follicles of vibrissae are surrounded by a highly developed
sheath of muscle tissue which can be used to move the whiskers. Whiskers can grow extremely long; the whiskers of a chinchilla
can be up to a third of its body length.
Vibrissae offer an advantage to animals that do not always have sight to rely on to navigate, or to find food, or when the
usefulness of non-tactile senses is limited. Some animals, such as house mice, can detect air movements with their vibrissae.
A large part of the brain of many mammals is devoted to processing the nerve impulses from vibrissae because it is important
to their survival. Mammals use a great deal of energy to keep the follicles housing their whiskers warm and ready to use.
Many cats have impressive whiskers. The longest whiskers belong to a female Maine Coon called Mingo, owned by Marina Merne
of Turku, Finland. In July 2004, one of Mingo's whiskers measured 6.8 inches (17.4 cm). Admittedly, not many owners have bothered
to measure their cats' whiskers.
Rex-furred cats frequently have curly whiskers as well as curly fur. Usually the whiskers form long, looping curls although
in some Rex breeds the whiskers are so brittle that they break easily, leaving the cat with short stubble.
Beneath the skin a whisker's follicle is about three times deeper than that of a normal hair. A special blood-filled capsule,the
sinus,acts like hydraulic fluid and amplifies the signal sent to the web of sensory nerves around it.
The above article was written by: Thomas Lopez, DVM