I was thinking about trying to integrate my babies (about 4 weeks) into the coop with my big girls. It's been warm here, probably averaging in the 80s every day but it usually gets kinda chilly at night. Is it a good idea to move them now, or should I wait a little longer? They are pretty well feathered now, and I don't think they would be too bad off if it only got to the 70s at night. I could even put a heat lamp in, though I would rather not. Suggestions?