To understand your hamster better, you need to know a little about how it would live if it were wild.

Golden hamsters come from hot desert lands, where they burrow under the ground to shelter from the heat of the sun during the daytime, and only came out to look for their food when it is cool in the evening.  That is why your hamster sleeps during the day, and is awake and busy at night.

Food is hard to find in the desert.  A wild hamster would travel far from its burrow, searching in the sand for seeds and the occasional green plant.  Your pet hamster does not have to forage for its food but still needs a lot of exercise.  So it must have room in its cage to move about freely, an exercise wheel to run in, and perhaps a ladder to climb up and down.

Wild hamsters hoard foods when it is plentiful, in case of a shortage later.  Hamsters have special cheek pouches into which they can stuff food and carry it back to a store in their burrow.

The instinct to hoard is still in a pet hamster. So, although you will be there to feed it regularly, your hamster will also use its cheek, pouches and store food behind its nest.

Golden hamsters re solitary – each one living alone in its own burrow , which it defends fiercely.  That is why hamsters must be caged singly, or they will fight for ownership of the cage.

Source: Taking Care of Your Hamster by Helen Piers