Kittens are the young of domestic cats; they are born with fur but have their eyes and ears closed and are helpless. Their eyes begin opening when they are about eight days old and can focus when the kitten is two to three weeks old.
By the time a kitten is three weeks old, it can hear well and its legs can support its body. Up through seven or eight weeks of age, the kitten is developing its coordination, motor skills and social skills. It begins exploring its world and grooming itself and its litter mates. Kittens usually make the shift to eating solid food when they are six or seven weeks old but may still nurse from their mother. During this period, gentle handling 15 to 40 minutes a day helps develop a kitten's learning abilities.
Kittens become extremely active and playful by the end of their second month of life. Play behaviors include wrestling with litter mates, pouncing, ambushing, tail chasing and leaping. They learn social behavior by observing their mother. When kittens begin depending more on litter mates for developing social skills at 10 to 12 weeks, they are ready to leave their mothers and go to new homes where they can continue their social development with their human families. Kittens enter adolescence when they are about six months old and become adults mentally and physically by the age of two years.