The proper term for a group of kittens is a kindle, litter or intrigue.

All cats are born with blue eyes. Their adult eye color will begin to appear in 3 to 12 weeks. As a result, eye color is not recorded on CFA registration records except in the case of white cats. White cats whose eyes remain blue have a high chance of deafness. Those with only one blue eye will likely be deaf only in the ear closest to their blue eye.

About 10% of a cat's bones are in its tail. These bones are called "caudal" vertebrae. A cat's tail, made up of these vertebrae, ligaments, tendon and voluntary muscle, is used primarily to communicate and to maintain balance.

When a cat kneads the ground, it's called snurgling. They develop this habit as kittens because it helps their mother produce milk!

Cats can make about 100 different sounds. A dog can only make 10.

Although it is a matter of some contention, there are approximately 70 breeds of domestic cat recognized by at least one major cat registry. The IPCBA (International Progressive Cat Breeders Alliance) recognizes 73 feline breeds, while the CFF (Cat Fanciers' Federation) recognizes only 32. The CFA (Cat Fanciers' Association) strikes a middle ground, recognizing a total of 41 breeds. At the center of this controversy are breeds such as the Savannah or the Bengal which the more conservative registries refuse to recognize because they were bred from "wild stock".

The first major cat show in the United States was held in May of 1895 at Madison Square Garden in New York City. It featured 176 cats, including two ocelots, two wildcats and three civets. A brown tabby female Maine Cat named Cosie, owned by Mrs. Fred Brown, was named Best in Show.

The normal body temperature of a cat is approximately 102° Fahrenheit. If your cat has a body temperature over 104° Fahrenheit or below 99° Fahrenheit, you should contact your veterinarian immediately.

Siamese cats are sometimes cross-eyed due to the abnormal uncrossed wiring of their optic chiasm, the part of the brain where the optic nerves partially cross, with those parts of the right eye which see things on the right side connecting to the left side of the brain and vice versa. In some Siamese cats, this wiring is disrupted because there is not enough nerve crossing. In order to compensate for the lack of this connection in their brains, cats with this defect will cross their eyes. Albino tigers sometimes suffer from a similar condition.

If a male cat is both orange and black, he is probably sterile. Both of these colors are carried on the female X chromosome that cats receive from their mother. Normal male cats only carry one X chromosome, so they can be orange or black, but not both. Under extremely rare circumstances however (1/3000), a male cat is born with an extra X chromosome (XXY), in which case it is possible for him to be both black and orange. This unusual combination of chromosomes, however, will almost certainly render the male cat sterile.