Kittens can be adopted at different ages depending on the situation. Here are some key points from the search results:

• Kittens are dependent on their mother for the first few weeks of life, and it is essential for their physical, psychological, and social development that they are not separated from their mother too early.
• Kittens are fully weaned by 8 weeks, but for the first two weeks, they drink only their mothers milk, which provides antibodies to help prevent infections.
• Kittens can be adopted starting at 8 weeks at most shelters and rescues, but breeders may wait until the kitten has been with their mother for at least 12 weeks, with many breeders waiting until 14 weeks.
• Waiting until a kitten is at least eight weeks of age before they are adopted or purchased will help to ensure that the kitten has had some opportunity for behavioral development and has at least received adequate amounts of their mothers milk for growth and overall health.
• Ideally, kittens should go to their new home around 12 weeks of age, while some kittens can go home earlier. The closer you wait until 12 or 13 weeks, the better off the kitten will be.
• If you would like to have some kitten experience but dont want to deal with a furry toddler, you could adopt an older kitten, 6 months - 1 year of age.

In summary, kittens can be adopted starting at 8 weeks, but it is best to wait until they are fully weaned and have had some opportunity for behavioral development. Waiting until 12-13 weeks is ideal, but adopting an older kitten can also be a good option.