Cats are born blind and deaf, and can not warm themselves. A cat's nose develops only when it's three weeks old, but it can tell its mother's taste from birth. At this time, the young cat has a very long sleep time, so if it is called, it is usually too cold, uncomfortable or hungry. The female cat will stimulate the young cat's anus with the tongue, so that the young cat will be excreted.

Kittens are about one hundred grams of weight when they are born, and their weight doubles after about two weeks. A kitten within two weeks of age has a normal heartbeat of more than two hundred times per minute, breathing at a rate of about 15-35 times per minute. The body temperature of the newborn kittens is low, about 35-36 degrees centigrade, and will rise slowly within 1-2 weeks after birth, until about 37.7 degrees centigrade at the age of four weeks.

Kittens have pain at birth, but neuromuscular reflex associated with pain develops only at 7 days of age. On the 5-14 day after birth, the eyes will be opened. The iris will then be gray and blue, the so-called gray blue eye. In the next few weeks, the eyes will gradually become the color of the cat, but the kitten will have enough normal vision at about 3-4 weeks of age. At the age of 7-14, they begin to crawl slowly. On the 16th day, they begin to sway and learn to walk. On the 21st day, they become more mature and steady.

Cats usually have to walk for third weeks before they can walk steadily. Before that, cats can only be moved by their kittens. The cat will grow its first set of teeth at two weeks and can basically go to the bathroom for three weeks. Cats will also start to play, around the big cats will bite each other to play, but also learn how not to hurt each other. The cat began weaning at fifth weeks, and began to eat hard food and became independent. At this time, the cat's sense of balance has been fully developed, also know how to comb hair. This period is the stage of cat learning. They must learn to recognize themselves and other animals.

Two months after birth, the cat's muscles are fully developed, but more exercise is needed to accurately determine distance, height and speed. The skill of hunting was also learned in this period. Generally speaking, kittens are best to leave their mothers after they are three months old, because when they are three months old, they have a sense of territory and a good sense of direction.