The Syrian Hamster or Golden Hamster, Mesocricetus auratus, is the best-known member of the rodent subfamily Cricetinae. In the wild they are now considered endangered, but are popular as house pets and scientific research animals. Adults grow from 5 to 7 inches (12.5 to 17.5 cm) long, and will usually have a lifespan of 2 to 3 years.
Like most members of the subfamily, the Syrian Hamster has expandable cheek pouches, which extend from its cheeks to its shoulders. In the wild, hamsters are larder hoarders. They use their cheek pouches to transport food to their burrows. If food is plentiful, they will store it in large amounts.
Sexually mature female hamsters come into season every four days. Putting a male and female hamster together when the female is not in heat may result in the female attacking the male. Syrian Hamsters have the shortest gestation period in any known mammal at only 16 to 18 days. They can produce large litters of 20 or more young. The average litter size is 8. If a mother hamster is inexperienced or feels threatened, she may abandon or even eat her pups. It is inadvisable for inexperienced owners to breed them.