Hi, We have 5 hens. All of them are living happily and they all started laying at the same time. Except one. She's not going well and she never laid a single egg. They are all 31 weeks old Ameraucanas. The problematic hen started ripping off her feathers at the base of her tail about one month ago. They grew back and she plucked them out again. She then started isolating herself, staying in the corner, not moving much all day long. We took her inside to check her out. No visible parasites on the outside and no worms in her stools. But things are getting worse. She eats and drink well, she makes normal stools but she barely moves and she tips over easily. She cannot walk well and she doesn't fly. She looks and act lethargic but she eats and drink normally. No breathing issues or anything. Any ideas? We're keeping her in a small room in the basement until we find out what's going on with the poor thing. Thanks!