Ordering my new coop. I have the option to have a heated roost installed. I live just North of Philadelphia. My flock is going to be composed of Rhode Island Reds, Barred Rocks, and Black Australorps. Looking for experience with heated roosts, advantages, disadvantages, or even if a heated roost is necessary. Is different heat source better (light, etc.). Thanks for all input. I know I can depend on the members for the info!!!