Help. Yesterday, we found one of our chickens dead in the cage. They are about 5 weeks old and we noticed that some of the chickens were pecking at the chicken that didn't have long tail feathers like the rest. We are now noticing that some of the chickens have some bald spots around their necks. Is there anyone who may know what is going on? I sure don't want to lose any more chickens because of my lack of knowledge.