Sleep

Cats are the undisputed sleep champions of the animal kingdom. Only the notoriously slow-footed sloth, which sleeps away an estimated 80 percent of its life, catches more shut-eye. Although the number of hours a cat spends sleeping can vary considerably among individuals, felines spend an average of 16 hours per day in slumberland.

No one is quite sure why, but the solitary cat's lifestyle, punctuated by frenetic, energy-draining bursts of hunting and playing, is thought to necessitate this form of energy conservation. In fact, sleeping wildcats are often described as "resting for the hunt." Because they consume so much energy in taking down large, wily prey, wildcats usually sleep even more than domestic cats. Female lions, the primary hunters of the species, have been known to rest or sleep as much as 20 hours a day.

The cat's diet is also thought to be a contributing factor to its ability to sleep so much. Large grazing herbivores need to feed for hours on end to get enough nutrition to survive and generally only have time to sleep four or five hours a day. The protein-rich diet of the feline, on the other hand, requires no such investment of time for daily sustenance. Instead of eating all day, the cat can stock up on sleep for its short, high-energy chases.

Ears and Hearing

The cat's ear is yet another marvel of feline engineering. Like a sophisticated satellite dish turning to pick up a signal, the cat's external ear, or pinna, rotates up to 180 degrees to locate and identify even the faintest of squeaks, peeps or rustling noises.

While dogs are renowned for detecting high-pitched whistles far beyond human hearing, cats actually hear much higher frequencies than canines and are only slightly inferior at the low end of the frequency scale. They also can detect the tiniest variances in sound, distinguishing differences of as little as one-tenth of a tone, which helps them identify the type and size of the prey emitting the noise. This heightened sense of hearing is especially important in wildcats, which depend on hunting for survival. It also enables wild and domestic feline mothers to hear faint squeals of distress from their cubs or kittens when they stray too far away.

A cat up to 3 feet away from the origin of a sound can pinpoint its location to within a few inches in a mere six one-hundredths of a second. Cats also can hear sounds at great distances - four or five times farther away than humans.