My mice are kept outside on a sheltered deck, and inside what we call the ‘mouse hutch’. The shade cloth on the front allows for ventilation, but keeps the sun off. The top, back and sides are a slightly reflective, waterproof material that’s stapled on. This photo was taken when the mice were first put in there in 2009. I didn’t get progress shots for the construction, but here are some shots of the final product. Pretty happy with it!