People become hamster breeders by uniting a male and female hamster while the female is in oestrus, or sexually receptive, and raising the resulting hamster pups. Because females of the species most commonly kept as pets, Syrian or golden hamsters, have five to 20 pups several times a year, it is important to have enough cages to house them and a pre-established outlet for sale, such as a pet shop.
By 4 to 5 weeks of age, Syrian hamsters are already sexually mature and must be separated according to sex to prevent premature breeding and fighting. The ideal time to breed females for the first time is when they are 4 to 6 months old. If they are bred too early, the resulting litters are small and weak, and if they are bred too late, birthing complications tend to develop. A female ready to breed should be put into the male's cage. If she is receptive, they quickly mate several times within 30 minutes. If not, she begins to fight the male. If this occurs, they must be separated, and breeding can be attempted again the next night. Females are in oestrus every 4 days.
Once females become pregnant, the gestation period is 16 to 18 days. The mother nurses the babies for about 21 days. During this time, it is important not to touch the pups or disturb the nesting material as the mother may cannibalize her babies. Once they are weaned, the babies need to be separated from the mother and kept in separate cages according to sex. When they are 6 to 8 weeks old, they need to be caged alone to prevent fighting. By the time they are 5 weeks old, they are fully independent and can be delivered to the pre-arranged sales outlet.