So, I done the chicken brooding thing a couple of times now but I'm getting 3 Khaki Campbell ducklings (3 weeks old) tomorrow and want to know how long I need to "brood" them before they can go outside to their house and run. I'm in Northern New Mexico so it is getting cold at night, not freezing by any means. And once they are outside in their pen, should I lock them into their pen? The run is fully enclosed. Thanks for the advice!