Female cats, known as queens, can become sexually mature from just four months of age. Once sexually mature, queens have regular heat cycles during which they may demonstrate restlessness, calling and wailing, squirming, rubbing and presenting the rear in attempts to attract a mate.
These periods of reproductive activity, lasting a few days, recur every few weeks during the breeding season, which usually runs from February to August. During these heat cycles, a queen will be very attractive to unneutered male tom cats. Males can detect her scent from several miles away and will make great efforts to reach her.
Queens are not selective and will accept advances from any tom, including relatives. Allowing an unneutered female outside - or indoors with an unneutered tom - will put her at risk of pregnancy, as well as putting her and any resulting kittens at risk of infectious diseases that unneutered roaming toms may carry.
Between one and nine kittens will be born in a litter - most commonly four to six.