A hamster is a small rodent that belongs to the subfamily Cricetinae. They are known for their furry bodies, short tails and tiny eyes. Hamsters are nocturnal animals which means they are active during the night and sleep during the day. Some common species of hamsters include the Syrian hamster, the Chinese hamster, and the Roborovski dwarf hamster among others. They are popular as pets due to their small size, ease of care, and low maintenance requirements.