Hamsters are solitary. Fights can even break out between different hamsters living together in one cage, and they can sometimes be grim. So it is best to keep your hamster alone. But make sure that the animal does not get bored! Hamsters are active and playful and must be free to enjoy themselves. 

The ideal cage for a hamster measures at least 80 by 50 cm, but the bigger, the better of course. Provide toys in which the animal can climb (not too high, because a hamster does not have good depth perception); and a wheel, to run in to its heart's content. Sprinkle the bedding richly on the ground, because hamsters like to dig tunnels and love to build underground burrows. 

Also make sure that the cage closes well, but is not completely closed, so that it is adequately ventilated. Furthermore, it should be easy to clean, because it should be cleaned weekly. At the same time, check regularly to see if the hamster is not able to escape, because they like to do so!