Mouse quasi-ecosystem

Question
I would like to set up a mini "ecosystem" for my mice (I would provide water, of course).  I have two female mice in a screen-top glass terrarium.  How would I go about doing this?  What edible plants could I use that are safe and won't be uprooted or completely destroyed by them?  Is simple potting soil okay to use?

Answer
i wouldnt do this.  soil can carry germs and it would be much harder to clean out.  however you can give them small amounts of grass/cress and wheat which they would eat in the wild.  It is more hygenic keeping them on wood shavings or wooden cat litter.  

There is a more natural bedding instead of wood shavings called hempcore or aubeose or carefresh.  it is made from a rainforest plant.
add treated wood from fish and aquarium shops to make it more natural and hide their food in places to make them search for food