I have one-year-old hens. About 40 of them. They are eating more than they ever have and in the last 2-3 days have almost stopped laying altogether. They are shacking their heads like when they have runny noses but they don't. Some are scratching their eyes. I have checked them for mites and lice and have not found any. Their feathers or rathered and they look like they're losing bodyweight. I ran a dose of roost boost dewormer through them about a month ago. Couldn't tell if that help much. Haven't noticed any warms in their droppings. What in the world is going on.