Kitten Birth and Development
A litter of kittens usually consists of three to six kittens. Born after approximately 63 days of gestation , kittens emerge in an amnion which is bitten off and eaten by the mother cat. For the first several weeks, kittens are unable to urinate or defecate without being stimulated by their mother.
They are also unable to regulate their body temperature for the first three weeks, so kittens born in temperatures less than 27 °C (80 °F ) are at risk for death from exposure if they are not kept warm by their mother.