It is typical for the male to help raise the kittens[citation needed] . If left together, the mother will often wait months to wean her kittens, even though their development is fairly rapid once they leave the nestbox[citation needed] . Breeders expect one to two litters per year, per breeding pair. Sometimes two litters may come closely in a row, with a longer period of time before further reproduction. Sexual maturity is usually reached at around eight to ten months of age.