Leonardo da Vinci called them "Nature's Masterpiece." In ancient Egypt they were worshipped as gods and goddesses of the sun and moon, and killing them was a crime punishable by death. Cats are clean and have been praised for their mysterious, exotic looks. They are fun to watch, whether they are stalking a toy, your ankles or a snack. And they are noted for their keen senses: their sharp hearing, sense of smell and touch, and the ability to see in near darkness.
Your cat's senses evolved from those of the wild cat's, a long line of hunters and predators, and are designed for the purpose of stalking, hunting and killing. Almost all of your cat's five senses have heightened ability when compared to humans.
The first thing your cat does when he climbs onto your lap is smell – your lap, your hands, your clothing. Before he digs into his food, he will sniff it; before he takes a treat, he will sniff it. And have you ever tried hiding medicine in his food? I'll bet it was a solitary object lying in the bowl after he finished.
Your cat's sense of smell is superior; it is one of the ways in which he interacts with his environment. His nostrils are working constantly. His nose is small and neat, but hidden behind it is a maze of bones and organs. Cats have 19 million odor-sensitive cells in their noses compared to 200 million in dogs and about 5 million in humans. In the roof of the mouth is a taste and smelling organ called the Jacobson's organ, a tiny cigar-shaped organ that links the senses of taste and smell. He uses it to sniff out things like a potential mate, a strange cat in his territory or an unusual odor.
Cats are equipped with glands that secrete pheromones, which are identifying scents akin to fingerprints in humans. These glands are found on your cat's cheeks, on his lower legs, and under his tail. He deposits his scent marks as he walks, when he rubs his cheeks against something or when he sprays. Another cat will identify these scents and will gather information, such as the identity of the cat (if it's one he knows), when he was there, which direction he headed, and even what kind of mood he was in.
Keeping in mind that your cat evolved from hunters, you can understand why his sense of sight is one of his strongest. He can scan your backyard with a single sweep of his eyes and detect the tiniest of movements from the tiniest insect. He can see in the dimmest of lights; his eyes can open about three times as wide as the human pupil and let in as much light as possible at the normal "hunting" times of dawn and dusk. He also has about three times as many rods (the receptors that are sensitive to light) than we have.
But letting enough light into the eye is not enough; your cat's beautiful eyes also have a reflective layer at the back called the tapetum ludium. This accounts for the reflective glow you see when your cat's eyes reflect light. Also, to make sure his sensitive system isn't a problem during the day, he can shut his pupil size down to a fine vertical slit so that only a small amount of light enters the eye. His retina is limited in size and by giving more space to rods than cones (the cells that recognize color), he probably sees some blues and greens but not reds – they probably look gray.
A final protection is the third eyelid – a thin fleshy membrane that is usually tucked away at the corner of the eye, but that can be used rapidly for protection. It reduces the intensity of bright light, affords some protection from eye damage in a fight or in pushing through prickly undergrowth, and it helps to clean the eye. You might see it when your cat isn't feeling well.
Your cat is sound asleep in the back room of the house when you open a can of soda. Nothing happens. Later, you open up a can of cat food. Suddenly your kitty is there, stretching and looking sleepy and hungry.
A cat's sense of hearing is amazing. Cats can hear high frequency sounds we cannot. The upper range of hearing in cats is about 60 to 65 kiloherz, which enables them to hear both their kittens and the ultrasonic calls of rodents. They can also distinguish the tone or pitch of sounds better than we can. And their ability to locate the source of a sound is highly advanced. From a yard away, a cat can distinguish between sound sources only 3 inches apart. They can also hear sounds at great distances – four or five times farther away than humans.