Lately the popularity to keep different species of dwarf hamsters has increased in Sweden. The requirements of the Swedish legislation to keep hamsters as pets are low which could be a reason for the increasing popularity. Hamsters are in nature generally nocturnal and can travel far distances to find food sources during their active part of the day. Their eyesight is poor, but is compensated by their well-developed hearing and olfaction. ?Run about balls? are made of plastic and the hamster is placed inside it where after the ball is placed on the floor and the hamster can then run protected outside the cage.