Kittens that are just over a month old can defecate on their own. In the early stages after a kitten's birth, the muscles around its anus are not yet fully developed, so it cannot defecate independently. At this time, if the mother cat is taking care of it, she will stimulate the kitten to defecate by licking its anus, and will also lick and swallow the feces.
As kittens grow and develop, the muscles around their anus gradually mature, allowing them to defecate independently. Furthermore, the amount of feces a kitten produces will increase as it eats more food.
