In any case, the animals enough litter (about 20cm) offer that they can dig. Unfortunately, keeping up with the normal small animal litter the hallways not very good. Straw, cardboard tubes of various kinds (big enough to climb through), hay and other scattered locations stabilize the aisles. You must experiment with some scattered places and the right place.
Also can not be missing a drinking opportunity. The most suitable small animal watering (which can be fixed with a suction cup or adhesive Velcro on the glass). Bowls go, the water is dirty but are very fast or zugebuddelt.
A food dish does not need. Sprinkle the food simply to scatter.
A container that is used as a sand bath file. Candy jars are well suited here, because the races can carry the sand here is not so easy from the container. Care must be taken on a secure footing. So do not just make up on the fringe!
A shelter option that is large enough for all of the mice should not be missed. It is not necessarily a house. One level below which they can hide Renner enough already.
A wheel is optional. Some use it very much, others leave it to the left and dig better. That's up to au to the animals. If you would like to offer one should make sure that the risk of injury (no shear effect by cross members, continuous treadmill).
Toilet paper rolls, kitchen rolls etc are gnawed very much. So fast you can not even look sometimes. As nesting material should handkerchief / toilet paper etc are offered. Furthermore, hay. It is enough simply to put these things in the cage, the mice build their own nest then