My chicks were 3 weeks old on Sunday. (so they're 3 1/2 weeks now). I moved them into their coop today because they have outgrown their box and were constantly flying up and knocking over their water bottle soaking all of their wood shavings. They were all on top of each other too in the box. Is it too early for them to be outside overnight? They have ruined their box by dumping the water so I cannot use it any more. The low for tonight is 60. The high today was 90. Do I need to put a heat lamp in there for them? They seem to be really happy in their coop.