This is the aviary used to house my four females. It is 6ft hexagonal with a 3ft by 2ft6ins porch on the back with double entry gates and large house over.
 
Available from Bransby Bunny 01427 788385
They need plenty to occupy their time, ladders, ropes branches (fruit tree) bog wood and tunnels.
When buying a cage or aviary, the bigger the better. For an indoor cage at least 1.2m high should be the minimum. It can be made of all wire mesh or wood and mesh. Make sure the holes in the mesh are not to big, aim for 1cm and make sure it is strong. Mine is made for parrots. A large nest box should be provided for each chipmunk. Use sawdust and good quality hay for bedding.
My aviary is built on a wall of brick on a slab base, leaving small cracks for drainage. In the base I have put some strong plastic pipes as tunnels and covered this with a 10inch layer of peat covered with bark chippings. This allows them to bury their food as they would in the wild. The entrances and exits to the tunnels are partly covered with logs.
In the center of the aviary they have a large wooden box filled with peat with access holes covered with a ceramic tiled top for their food and a roof similar to a bird table. There is plenty for them to do with logs, branches and ropes. They also have a wheel.
The main thing is to make their environment interesting and change it often!