Chickens are relatively smart as to what and what not to eat. The chicks are born with instinct to know what's ideal to eat. You may want to inspect your yard and just make sure that there are no little pieces of metal or plastic that they could eat, because chicks and chickens will eat things like that and mistake it for food. Other than that you shouldn't have a problem and they should be fine. As to your other question, it is perfectly normal. Chicks tend to be very drowsy and fall asleep quickly and they try to sleep as much as possible. And don't worry to much about the heat. Chicks need heat and warmth and it would have to be an extremely hot or humid day for the chicks to overheat. Hope that helped :)

I free range my three-four week old chicks sometimes when it's hot outside, and I'm worried that they'll eat something they're not supposed to; like they'll eat small pieces of cotton from my blanket, or even small twigs on the ground. I just want to know if this will harm them in anyway, and if they'll eat anything particularly dangerous if I don't watch them carefully. Thanks.

Extra question for my chicken experts: when I hold one of my chicks on my lap, and my lap is in direct sunlight (hot), it looks like s/he starts fainting almost, going limp in her leg and just falling asleep instantly. S/he'll "wake up" if I move. Is this normal?