I have 12 chicks that are probably around 1-2 weeks old, all have been healthy and fine. Yesterday night I noticed that one of my Rhode Island reds was kind of lethargic, he was sleeping more then the rest. I fed her separate from the rest and made sure she drank lots of water, she had a little more energy after eating but went back to sleep since it was night and the rest were sleeping. This morning I noticed that she was still tired and her wings were slightly drooping. The other Rhode Island Red was also looking lethargic now and had droopy wings, I brought them both out and fed them. They had a little energy again. The rest of the chicks have been acting fine, but I'm worried about coccidiosis. They are on a medicated feed and they haven't had any blood in their stool but they have been getting pasty butt. My barred rock who is slightly older also has been getting pasty butt, but he isn't acting any different. I also was concerned that the pasty butt could be from their brooder being too hot since my oldest birds were panting the other night. I moved the heat lamp to the other side of the cage, it was in the middle before, and raised it up some. The birds aren't panting now but the younger ones huddle so now I think they might be cold? There isn't a huge age gap, they are maybe half a week or a week older max. I'm going to buy some cored right now and am going to start treatment for five days today. I just wanted to hop on and see if anyone had any ideas and if I should do anything else. Thanks in advance also, is it normal for my chicks too huddle when they sleep under the lamp, or doesn that mean they are cold, they walk around the whole brooder but when sleeping they huddle under the heat. And my 2 black sex links who are the oldest pant but stay under the lamp, I move them to their roost and thy stay for most of the night, but thy won't move by them selves they will just stay panting. I know that older birds don't need as much heat, but that's also why I moved the lamp to the other side, so that they can get awY from the heat if needed. Sorry for the long post and again thank you. I'm new to chicks and have been trying my best, I don't want to lose any but I also know that chicks are fragile.