I have finished the coop here in eastern Massachusetts - it's pretty large and my 16 4-week-old chicks love it. I am beginning work on the run now. I will have two side-by-side runs so I can alternate 2-3 months each. The runs will be predator-proof (owls, hawks, fisher cats, coons, coyotes, probably skunks) - steel 2x4 fencing, roofed with same fencing, 4-foot apron, 1/2-inch hardware cloth from ground up 3 feet on all sides, two small, red lightbulbs eyeballs-width-apart on coop wall, plus me and my .22 rifle. How old should the chicks be before they go outside into the protected run? I have no other chickens - just these 16 4-week-olds. It's 60 at night here, 90 in the day. Thanks for any advice.