Kittens typically start to show an interest in solid food at around 4 to 5 weeks of age, although this can vary depending on the individual kitten. At this stage, their teeth are starting to come in and they are becoming more active and curious about their surroundings. They may begin to nibble on solid food, but will still rely mainly on their mother's milk or a milk replacement formula for nutrition.
As the kittens grow and develop, their interest in solid food will increase, and they will start to eat more and more of it. By the time they are 8 to 10 weeks old, they should be fully weaned and eating solid food exclusively.
It's important to introduce solid food gradually and choose a high-quality kitten food that is appropriate for their stage of development. Consult with a veterinarian for specific recommendations on feeding your kitten.