Cute kittens

A kitten is a juvenile cat. After being born, kittens display primary altriciality and are totally dependent on their mother for survival. They do not normally open their eyes until after seven to ten days. After about two weeks, kittens quickly develop and begin to explore the world outside the nest. After a further three to four weeks, they begin to eat solid food and grow baby teeth. Domestic kittens are highly social animals and usually enjoy human companionship.

A Ragdoll kitten
Etymology and development

A kitten opening its eyes for the first time

A pair of sibling kittens from the same litter at 11 weeks old
The word "kitten" derives from the Middle English word kitoun, which in turn came from the Old French chitoun or cheton.[1] Juvenile big cats are called "cubs" rather than kittens; either term (but usually more commonly "kitten") may be used for the young of smaller wild felids, such as ocelots, caracals, and lynxes.[2]

A feline litter usually consists of two to five kittens[3] born after a gestation lasting between 64 and 67 days, with an average length of 66 days,[3] but from one to more than ten are known.[4] Kittens emerge in a sac called the amnion, which is bitten off and eaten by the mother cat.[5]

For the first several weeks, kittens cannot urinate or defecate without being stimulated by their mother.[6] They also cannot regulate their body temperature for the first three weeks, so kittens born in temperatures less than 27 °C (81 °F) can die from hypothermia if their mother does not keep them warm.[7] The mother's milk is very important for the kittens' nutrition and proper growth. This milk transfers antibodies to the kittens, which helps protect them against infectious disease.[8] As mentioned above, they cannot urinate, so they have a very high requirement for fluids.[9] Kittens open their eyes about seven to ten days after birth. At first, the retina is poorly developed and vision is poor. Kittens cannot see as well as adult cats until about ten weeks after birth.[10]

Kittens develop very quickly from about two weeks of age until their seventh week. Their coordination and strength improves. Kittens play-fight with their litter-mates and begin to explore the world outside the nest or den. They learn to wash themselves and others as well as play hunting and stalking games, showing their inborn ability as predators. These innate skills are developed by the kittens' mother or other adult cats, who bring live prey to the nest. Later, the mother demonstrate hunting techniques for the kittens to emulate.[11] As they reach three to four weeks old, the kittens are gradually weaned and begin to eat solid food, with weaning usually complete by six to eight weeks.[12] Kittens generally begin to lose their baby teeth around three months of age, and have a complete set of adult teeth by nine months.[13] Kittens live primarily on solid food after weaning, but usually continue to suckle from time to time until separated from their mothers. Some mother cats will scatter their kittens as early as three months of age, while others continue to look after them until they approach sexual maturity.