Why do cats have whiskers, and can you trim them?

Whiskers, technically vibrissae, are specialized tactile hairs embedded far deeper than ordinary fur in follicles packed with nerve endings and blood vessels. They detect minute changes in air currents, register contact with objects before the face reaches them, and transmit information about the size, texture, and position of things nearby. A cat's facial whiskers roughly match the width of its body, which is the basis of the folk observation that cats use them to judge whether an opening is passable. Cats also have whiskers above the eyes, on the chin, and on the backs of the front legs, the last of which help track prey held in the paws.

The sensitivity is high enough that the whiskers function as a near-field sensing system, letting a cat hunt in darkness by detecting the air disturbance of moving prey and locate it precisely for the killing bite. Whisker position also communicates mood: forward and spread during curiosity or hunting, flattened back against the face in fear or aggression.

Trimming or cutting whiskers is harmful. Because the cat's spatial sense depends on them, removal produces disorientation, misjudged jumps and gaps, and evident stress, and it is regarded by veterinarians as a welfare issue rather than a cosmetic one. Whiskers shed naturally and regrow, so finding one on the floor is normal. A related consideration is whisker fatigue, the discomfort some cats show when deep narrow food bowls press their whiskers repeatedly, which is why wide shallow dishes are recommended and why a cat that paws food out of a bowl or eats reluctantly may be responding to the bowl rather than the food.