They usually walk on all four, which results in a cute hopping movement because of the length difference between the front and hind legs. When the animals are in a hurry they will only use their hind legs and can make huge jumps. To house a group of Australian hopping mice off course you need a tank that is big enough. An old aquarium of minimal 100 cm can do very well. Although these are desert animals, sand is not recommended as bedding material.
Sand is cold and pollutes rather quick.
Sawdust, corn cob or hemp fibers are much more suitable. Give them in addition a sand bath, the animal can dig in it and groom their fur. With some branches, bark, hay, toilet rolls and stones you can create a wonderful exciting environment for your animals. They also need a nesting box, make sure the whole group fits in, because as said before, they all sleep together. A nesting box with a high entrance is preferred, this way pups will not be dragged outside while they are drinking and their mother leaves the nest.