Thought you might be interested to see te finished set up. It houses two resued gerbils who seem to love the space, the digging, the chewy cardboard - in fact it's gerbil heaven. The second level is made from a seed tray which slots into the base quite nicely. This is so they can access the food and water without messing up the litter.
And one of the occupants, Gerbillus Maximus (Rita) at the water bottle..
the good thing about gerbils is that they are active at sometime in the 24 hours so they are easily seen unlike Syrian hamsters which only come out from 9PM onwards. The dwarfs are out in the day but not as much as the gerbs.