Cats have a set of specialized hairs that we call whiskers and scientists call vibrissae. These hairs are longer and thicker than regular hairs and their roots are also embedded much deeper in the flesh. Whiskers are present on top of the eyes and upper lip of the animal as well as on the chin, forelegs, and ears. Each whisker is connected to a sensory structure called a proprioceptor which sends its signals to the brain, so you can think of whiskers as very sensitive tactile hairs. Whiskers allow the cat to balance its body, sense its environment, and communicate emotions. About 40% of the area of the sensory centers of the cat’s brain is involved in processing the input from whiskers!
One particular thing that differentiates whiskers from other hairs is that whiskers are attached to special striated capsular muscles that can be moved voluntarily by the animal. Although people do not have whiskers, 35% of human beings have what seem to be remnants of these striated whisker muscles in their upper lips. These vestigial muscles are evolutionary remnants of the muscles that moved the whiskers of our whiskered ancestor.
In the images below, you can see several views of Science Cat’s head showing her whiskers.
The images belong to the author and can only be used with permission.