I bought 8 Buff Orpingtons yesterday. They are about 4-6 weeks old. They only have a little fuzz, mostly feathers. I have a light for them for heat as awell as chick feed. Is there any thing else I can do for them? This is my first time with chicks. Also, what behaviors and signs will help me to sex them? I tried to picks what I thought were pullets based on having smaller combs than others that they had, but I'm sure I probably did not guess 100% right. At what age should I be able to tell for sure?