The mating period is from April to June. To show that she is ready for mating, the female squeaks loudly. The babies are usually born in litters of three to seven, after a gestation period of 23 days. The babies are blind and have no fur when they are born. They open their eyes after about eighteen days. They are nursed until they are one month old. When they are two months old, they live on their own. They become ready to mate when they are a year old. They will normally live for about five years.