[These two photos] show Sparkle (Silver Wyandotte) drinking from the inner waterer, a five-gallon food-grade bucket with two nipples. I drilled a 1/32-inch hole in the lid to prevent a vacuum and keep out dirt. I have a mirror against one wall and thought that a heat lamp on a thermal switch would be enough to keep the water in the bucket from freezing. This winter we had lots of single-digit days and nights and the water never froze.