When are cats said to be in season?

CATS IN SEASON

A female cat can be in season five times a year. It is only during these periods, which last about five days  each, that the cat is fertile. Her mating call is a shrill caterwauling. The domestic cat, as a rule, goes in season for the first time between the ages of seven and twelve months. Her pregnancy generally last two months. A few hours before she delivers her litter she stops eating. A normal litter of kittens is four.