my chicks are seven weeks old and two nights ago one died unexceptionably. I was scared it was a disease, so i cleaned everything really well. Then last night another died! I am really worried about the other chicks. They only seem to die at night though. During the day they are in a large outdoor pen, and at night they go into a small coop. also during the day they seem really energetic, and seem to have no problems. There water is always full and clean, and so is there food. I have them on medicated chick food, because they aren't big enough to eat normal feed yet. I cant figure out what it is!