Can I fit through this opening? Is there an obstacle blocking the path? Have I got a good hold on this mouse I’ve captured? For a cat, these are important questions — all of which can be answered with the help of his whiskers.

At the tips of the whiskers are sensory organs called proprioceptors. “These receptors are very sensitive to pressure,” says animal behaviorist Myrna Milani, DVM. “Any time they come close to something, it triggers a sensation in the cat. This helps him detect the presence, size and shape of nearby objects he may not be able to see.”

Cats usually have from eight to 12 long whiskers that fan out sideways on each side of the upper lip, plus some tufts of shorter whiskers above their eyes, on their chin, and on the back of their forelegs, just above the paw.

The whiskers on a cat’s face are used to help him navigate in restricted spaces or in darkness. “Because facial whiskers generally extend outward to about the width of his body, a cat may use his whiskers to help it assess whether he’s going to be able to fit into a tight space,” notes animal behaviorist, John Wright, PhD. “When the whiskers are fully fanned out, it enables the cat to measure the width of the opening. If the whiskers touch the edges of the opening, the cat knows his body is not likely to fit through.”

Cats use the whiskers on their forelegs to collect information about their prey. Because cats are far-sighted, Wright says, “they may be too close to the animal they’ve captured to actually see it. However, the whiskers on the cat’s legs allow him to feel his prey and gauge the size, shape, and position of his prey, his own position in relation to the prey, and detect any escape attempts.”

In addition to having sensory properties, whiskers are also a means of communicating with other cats and with people. A cat will change the position of his whiskers, depending on his mood or situation. When a cat is walking, his whiskers are held out as far as they will go. When feeding or greeting another cat, the whiskers are held in close.

“If a cat is angry or feels threatened, the whiskers will be pulled back against his face,” Milani notes. “Otherwise, when the cat is happy, confident or friendly, the whiskers will be more relaxed and pushed forward.”

You should never touch or manipulate your cat’s whiskers — especially if in doing so the whiskers are moved in a position counter to their natural alignment. “It’s uncomfortable for the cat, and sometimes downright irritating,” Wright says.

It’s also important that you never cut or trim your cat’s whiskers. Regrowth of an entire set could take two or three months, and your cat would have a difficult time maneuvering around without them.

Cats do, however, lose whiskers as part of the normal shedding process. “But they don’t shed all of their whiskers at once,” Milani says. “They just lose a few at a time.” She says cats need to hang on to most of their whiskers so that they can stay in touch with the world around them.