I would like to also recomend a glass fish tank with a tight fitting screen that fits to that aquarium securely. And I also usually recomend getting companions for all animals as ThelmaLu recomended, but hamsters are extrememly terratorial and they will fight continuously, eventually killing one another...don't get a companion. They are one of the few exceptions to the rule that animals like companions. Hamsters are solitary and a companion would end up either stressing the hamsters so badly that they walked around their cage like it was layered in glass, or they would fight and kill one another. Those little critters sure can put up a fight!