Hi. I am hoping someone can help me. I have "babysat" baby chicks for friends before but now have 4 of my own. They are 3 weeks old. There is one that sleeps more than the others, especially during the day. Today I watched it sleep standing up (and on one leg) while the others walked around, chirping. The sleepy one has been eating and drinking but is not as active as the others. Could this sleepy chick be sick and if so what could be the cause?