I have a few chicks that are 1 week old. The other day i had one that was sleeping by it self and sleeping alot and when it would stand it will hang its head down as if it was very week and it wings would droop down. It died a few days later. I just that it was smaller than the rest that something wasnt right inside. But now i notice a few other ones are doing the same. I dont want to loose any more. Any advise what is going on and what to do.