I have four chicks that are ready to make their debut in the coop and two that are not. One is a silkie that is the same age as the "big" girls, and one is a RIR that is two weeks younger. My question: If I keep a heat lamp in the coop, can they all go out together? The two smaller ones will be quite upset if they are not with their flock. By the way, I'm in the Seattle area, where the low at night is the upper 40's, and high during the day is 60's. Thanks for your input!