A hamster cage is **way** too small. They need a large area to run around, such as a dog kennel run. With a little kiddy pool for it to wash its self and swim around in. Raccoons will eat a baby duck, along with many other wild animals. I hope you have no intention of setting it loose after raising it, what type of duck is it? If it is rather cold outside at night where you live, it is a good idea to have a small heat/incubation light to keep it warm. Or, you could get a big bird-like house and fill it up with hay for it to nestle in. Make sure they have somekind of ramp for getting in and out of the pool, otherwise they can get stick in the pool (and it is possible for them to drown). Do not put more than 2 inches of water in the pool, because they can get cold easily since they don't have oily feathers.

This is a pretty nice website, click here