Why do cats have whiskers?

Also known as "tactile hairs" or vibrissae, whiskers are the long, thick, flexible hairs on a cat's face. Whiskers are rooted very deep in the cat's face, in an area rich in nerves and blood vessels. In addition to having the long tactile hairs on their cheeks, cats also have shorter ones above their eyebrows, on their chin and on the back of Navigation Mood indication Measuring an opening Whiskers help the cat feel his way around. Whiskers are so sensitive that they can detect the slightest directional change in a breeze. At night, for example, this helps a cat slink its way through a room and not bump into anything.  How? The air currents in the room change depending on where pieces of furniture are located. As the cat walks through the room and approaches the couch, he'll know which direction to turn based on the change in air current around the couch. In addition to having sensory properties, a cat's whiskers are also a good indicator of his mood. When a cat is angry or feels defensive, the whiskers will be pulled back. Otherwise, when the cat is happy, curious or content, the whiskers will be more relaxed and pushed forward. But the whisker's primary use is to help a cat judge whether or not he'll fit through an opening. A cat's whiskers are roughly as wide as his body -- sort of a natural ruler. The whisker tips are sensitive to pressure. You'll probably see a cat stick his head in and out of an opening before he puts his body in. He's judging the width of the opening, and is determining if he can fit into it.