Under the Microscope:When driving home yesterday, I had to swerve suddenly to avoid a cat, which explains why today I write on the subject of the domestic cat, writes Prof William Reville
I don't have a pet cat, but we do have a dog. Cats relate differently to their owners than dogs do, generally behaving more independently and less overtly affectionate. Many people especially admire these feline traits, but I prefer the simple friendliness of the dog.
Domestic cats are descended from the Near Eastern desert wildcat Felis silvestris lybica. Cats were first domesticated 10,000 to 12,000 years ago, but the oldest archaeological evidence of a link between cats and humans is a grave excavated in Cyprus, estimated to be 9,500 years old. The likely origin of domestication was extension of human protection to a formerly wild animal in return for the benefit of removal of rodents from human food stores in early farming economies. Unlike dogs, which also hunt rodents, cats do not eat significant amounts of grains, fruits or vegetables.
By about 5,000 years ago, cats were well established in Egyptian households. They were used to hunt birds and fish as well as protect grain stocks from rodents. Laws were enacted to protect cats and a cult of cat-worship developed. The cat goddess Bastet had the head of a cat. Cats were well cared for and their mummified dead bodies were buried in special cemeteries. One cemetery found in the 1800s contained the preserved bodies of more than 300,000 cats.
Cats, valued as rodent catchers, were brought by the Greeks and Romans to most parts of Europe, and were also valued as pets and rodent catchers in India, China and Japan. During the Middle Ages in Europe, cats became objects of superstition and were associated with evil. People who kept cats were suspected of wickedness and cats were hunted and killed. As cat numbers declined, the rat population grew, which helped the spread of epidemics in Europe.
By the 17th century, the cat had begun to regain its former place in Europe as a companion to people and controller of rodents. Many writers kept cats and wrote of them. Cardinal Richelieu was a noted cat-lover. Widespread affection for cats continues to this day.
It is sometimes said that running a university is "like herding cats", referring to the general difficulty encountered in training cats. Domestic cats will live in colonies, but they hunt alone, unlike lions who hunt in groups. Cats are "clean" animals. Their saliva, used liberally during frequent grooming, is a natural deodorant. The relative lack of odour minimises the chance that a rodent will notice the cat in time to escape.
DOGS ARE RELATIVELY EASILY trained. Dogs hunt in packs, which requires co-operative effort and good communication skills. Dog odour is an advantage in pack hunting. The pack divides in two. One part goes up-wind of the prey and its odour drives the prey towards the rest of the pack located down-wind. The lone hunter doesn't require any such communication skills and this is surely part of the reason why interaction with cats isn't easy. Cats are often described as aloof, inscrutable and self-sufficient.
Undomesticated cats that roam freely are called feral cats. Semi-feral cats are common on farms where they control the rodent population. Domestic cats also instinctively hunt and kill rodents, birds, frogs, fish and large insects. They may not eat the kill and often present it to their owners. They may expect praise for this, or may even expect the human to eat the kill.
Cats have loose skin. This allows them to turn around and confront a predator even when the predator has a grip on them. The very loose skin at the back of the neck is called the scruff, where the mother cat grips to carry her kittens. Cats tend to become quiet and relaxed when gripped there.
Cats are highly specialised for hunting, probably as an indirect result of their inability to taste sugars and consequent lack of interest in plant foods. Their digestive tract is too short for effective digestion of plants but is consequently light, thereby assisting the speed necessary for hunting. Cats have specialised teeth and a digestive tract suitable for the digestion of meat. The cat's tongue has sharp backward facing spines useful for ripping and tearing meat.
Cats can move each ear independently of the other, and many muscles control each ear, allowing for a certain amount of directional hearing. Unlike most mammals, cats move by moving both legs on one side and then both legs on the other side. Most mammals move legs on alternate sides in sequence.
Cats have better night vision than humans and can hear much higher-pitched sounds. A cat's sense of smell is about 14 times as strong as a human's. Cats sleep on average about 14 hours a day.
Most breeds of cat have a fondness for heights. This is good for observation of surrounding territory and is also a good location from which to pounce on prey. If it falls from a high place, a cat reflexively rights itself by twisting its body so that it lands on its feet. The height required for most cats to do this is about 90cm (three feet).
Cats have appeared in the works of many great painters, and tales and poems about cats are part of general culture. Cats have inspired many poets, eg Edward Lear (1812-1888) - The Owl and the Pussy-Cat. Probably the best known cat in the world now is the cartoon star Felix the Cat.
• William Reville is Associate Professor of Biochemistry and Public Awareness of Science Officer at UCC - understandingscience.ucc.ie