Whiskers are really useful to your cat. They are highly specialized, sensitive structures which provide a continual source of tactile information about the environment. The scientific name for whiskers is vibrissae (derived from the Latin word vibrare meaning vibrate...I knew my high school Latin classes would come in handy someday).
It has been a long held notion that a cat's whisker length is the same as her body width providing a sort of built-in ruler to judge whether she can fit through an opening. It is true that whiskers give cats information about the closeness of objects. However, there is no real correlation between whisker length and the cat's width. The whiskers of fat cats do not grow to match their waistline.
Whiskers are attached to highly specialized nerves which can sense the most delicate touch or shift in air circulation. Cats are predators and whiskers help them gather information about the motion and location of their prey. This ability is most useful during the freeze phase of the hunting sequence which just precedes the pounce. During the freeze a cat fully focuses her attention on the prey and the timing of her pouce. She needs to know about the closeness and movement of objects in the immediate environment in order to be successful in catching her dinner.
Cats are also a prey species. These super-hunters are also hunted by larger animals. While she concentrates on her hunt she is at risk of being caught. As she is using her eyes, nose and ears to collect information about the rodent she has stalked, she also needs to be aware of her own safety. Having whiskers to collect information about changes in her environment without having to change her gaze is of great benefit.
But, here is my favorite part about these touch sensors: cats have very poor near vision. They have a hard time seeing things which are right under their noses because they are unable to focus i their eyes in this range. Now think about whiskers. Notice that in addition to the big, beautiful, laterally directed vibrissae there are many short whiskers nearer the tip of their nose that extend forward. These become the sensory organs cats use to locate objects that are too close for the cat to see! Have you ever noticed that when you drop a treat right in front of your kitty's face she doesn't see it right away? Watch her sniff and then start some subtle head bobbing toward the treat before she finds it. She is locating it with the help of touch from those short whiskers. Cats' eyes are better designed to focus on things at a distance. Now toss the treat a few feet away from her and see how fast she finds it.
Cats are so awesome!
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