Kittens go through a lot of changes very soon after they're born. The first few weeks of their lives are full of new sights and sounds, and by the time they reach six weeks of age, they are almost ready to leave their mothers. But that doesn't mean the growing, changing, and learning comes to a halt. Between the ages of six and 12 weeks of age, there are still several big milestones that a kitten needs to pass.

Physical Development

• At six weeks of age, a kitten's baby teeth will begin to erupt. Throughout the next couple of weeks, all of the baby teeth should break through the gums and the mother cat may be reluctant to nurse because of this. At 12 weeks of age, these baby teeth will then start to fall out.
• A kitten's eyes and ears have opened several weeks ago, but at six weeks of age, the eyes will still be blue. Hearing and vision are fully developed, and over the next couple of weeks, the eye color will slowly change to be the final adult eye color.
• Until about six weeks of age, a kitten will need supplemental heat to stay warm. Once it is about a month and a half old it will no longer need a heating pad, heat light, or another heat source that it was relying on. As long as the kitten is in a room temperature environment, it will be perfectly fine since it will be able to self-regulate its body temperature.
• If you have a male kitten, its testicles will drop and be palpable at about seven to eight weeks of age.

Behavior Changes

Between six and 12 weeks of age, a kitten is very active and social. It won't sleep quite as much as it did as a newborn, but it will still spend more than half the day napping. A kitten will start playing with its littermates, explore its surroundings, and its personality will start to develop. This time is extremely important for developing your kitten's social skills. If a kitten doesn't have the opportunities to learn right from wrong through playing and discipline from its mother and littermates, then it may have difficulty as an adult. Social skills may suffer in kittens who were not properly socialized or they could even develop aggression issues.

Health and Care

• At about eight weeks of age, a kitten should get a check-up with a veterinarian and receive its first FVRCP vaccine. The FVRCP vaccine contains three different vaccinations in one. FVRCP stands for feline viral rhinotracheitis, calicivirus, and panleukopenia. These are major diseases that cats of any age can contract. This vaccine will need to be repeated or supplemented with a booster vaccine three to four weeks later at about 12 weeks of age and once more at about 16 weeks of age.
• Some veterinarians will spay or neuter a kitten between the ages of eight and 12 weeks old while others will have a minimum weight requirement or recommend the kitten be closer to six months old before it receives this surgery. This procedure should be discussed with your veterinarian and a preoperative blood screening is often recommended to ensure your kitten is healthy enough for anesthesia. This blood screening will also establish a baseline for future blood screenings as your kitten ages, so you will have something to compare it to.
• Heartworm and flea treatments should also be discussed with your veterinarian. Not all products are safe for young or small kittens, but these parasites can be deadly to a cat, especially a small kitten. If you see fleas on your kitten you can bathe it with dish soap, but you should avoid flea shampoos, collars, or sprays. Also, never use products made for dogs on kittens or cats.

Food and Nutrition

A six-week-old kitten should be in the weaning process to transition away from nursing. High-quality, canned kitten food should be mixed with water to create a gruel until the kitten can eat the canned food without the added water. Then the kitten will advance to dry kitten kibble once it is comfortable eating canned food and it has its baby teeth. By eight to 10 weeks of age, a kitten should be fully weaned from its mother. There is no need to limit the amount of food a kitten consumes at this age.

Training Kittens

• Litter box training will come naturally to a kitten if they see their mother or littermates using a litter box. Covering their waste after urinating or defecating is something cats instinctively do.
• Teaching your kitten its name can be done once it is about eight weeks old through repetition and reward. Verbal praise, petting, toys, and treats are all forms of rewards that your kitten will respond to.