I took 5 silkies out of the incubator and put under heat lamp in tote. Later that night I realized one was rolling around and after observing more and holding him he's very tumbly and neck is always down. I thought he'd be dead by morning. But he's alive only still rolling and unbalanced & head down. And I see a second chick acting a little that way with neck down. Is it neurological or a genetic issue? Or were they in too cramped if a shell and just need time?