I live in the mojave desert and never thought frogs could survive here, but somehow at least 3 or 4 frogs manage to live on our property. I want to put in a pond for them, but I am concerned that in the winter when the pond freezes so will the frogs. I currently have a bird bath and a shaded area with cover for the frogs nearby that they use. What can I do to help these frogs in this extreme environment? Would a pond turn into a winter death trap?