It should be that the female cat has entered estrus. At this time, the cat will habitually make a unique sound at night to attract the male cat. At this time, the owner can consider finding a boyfriend for the cat and giving birth to kittens; if there is no mating, the cat's estrus will last for about three days, and the cat's meowing will be concentrated at night and very quiet during the day, and then it will slowly ease down.