Anatomy
We know that a cat’s whiskers are stiffened and enlarged hairs. They are in fact more than twice the thickness of ordinary cat hairs. The scientific name is vibrissae. They are embedded in the skin of the cat’s upper lip to a depth three times greater than is the case for ordinary hairs. They are supported and supplied by a mass of nerve endings which transmit information picked up by the whiskers to the brain.
Responsiveness
On average a cat has 24 whiskers. There are 12 each side of the nose. They are arranged in four horizontal rows. You can see them moving forwards and backwards. When they move forwards it is in response to a cat being inquisitive about something, in wanting to test something or is about to attack when the cat needs the sensitivity of her whiskers to help position the attacking bite. The whiskers move backwards when a cat is being defensive or deliberately avoiding touching something i.e. when feeding in a bowl.
Independent movement
The two top rows are moved independently of the bottom two rows. The strongest whiskers are in rows two and three.
Sensitivity
Whiskers are incredibly sensitive because, as mentioned, they are supported by a mass of nerves. They act as feelers, sensitive to touch. They’re so sensitive that they can detect air currents. When a cat is walking in the dark and needs to avoid solid objects her whiskers can detect slight variations in air currents around these objects without touching the object itself. This helps the cat to navigate at night.
Hunting
When hunting, her whiskers are vital, especially at night. At night whiskers can act as a “highly sensitive guidance system”2. It has been observed that if a cat has damaged whiskers she is unable to accurately bite her prey at night and therefore is unable to make a clean kill. With perfect whiskers domestic cats can kill cleanly in both dark and light conditions. In dark conditions the whiskers takeover helping the cat to make a split-second decision where to direct her bite which is to the nape of the animal’s neck to split the spine.
It is said that a cat’s whiskers can read the shape of a cat’s prey. Dr Desmond Morris1 likens it to a blind man reading Braille, allowing the cat to act very accurately and quickly.
Touch
Photographs of cats catching and carrying mice show that, when required, their whiskers are forwards and wrapped around the body of prey continuing to send back information in case the animal is still alive. They act like fingers touching the prey.
Nocturnal
We know that domestic cats are primarily nocturnal hunters, hunting at dawn and dusk (but they also hunt during the daytime). Therefore whiskers are an absolutely vital and integral part of a domestic cat’s anatomy.
Domestication
As an afterthought it could be argued that a domestic’s whiskers are gradually becoming redundant because this vital part of their anatomy is strictly speaking no longer required as the cat is fed by his owner. Perhaps they will gradually, over thousands of years, lose their effectiveness. Who knows?
Note: 1. Cat World pages 468 and 469.