I've got 11 bantam cochin chicks who are 2 weeks old today. They're in a makeshift brooder in my office with a heat lamp. They've gotten entirely too big for this brooder. I just set up a big brooder (made out of a watermelon box) in my garage for them. Can I move them out there, or are they still too young? I've got a 250 watt heat lamp out there, but the nights here are down in the 50's, and the days are only in mid 70's...for now. I can, if needed, add a second heat lamp for them.