My (I think) 4-5 month old dwarf hen has been lethargic and seems to not be eating for 2 days now. All my chickens except one rooster are the same age and none have laid an egg yet. She's the only one that's acting weird. Everyone else is happy and healthy. I have no idea what is going on. I think she drank a little last night. I have her separated in a large cardboard box with straw, food and water in it. I picked her up and check her nostrils and look for any wounds. Everything seems ok. Please help. They're my little buddies.