A kitten is a juvenile cat. After being born, kittens are totally dependent on their mother for survival and 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 adult teeth. Domestic kittens are highly social animals and usually enjoy human companionship.For the first several weeks, kittens cannot urinate or defecate without being stimulated by their mother.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.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. Newborn kittens are unable to produce concentrated urine, and so have a very high requirement for fluids.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.