kittens in heat

Question
When do female kittens go into heat for the first time?

Answer
Sometimes as early as 4-5 months, other times as late as 9 months. And not all cats have a noticeable heat (called a silent heat). If you plan to spay your kittens, and notice a deliberate heat (crawling on the ground with butt and tailed raised, sometimes marking on top of furniture, that lovely yowling) even at 4-5 months, make sure your vet will do an early spay, since most like to wait until 6 months. In case you need to wait and still plan to spay, just keep the girls under check until they go out of heat.