We have a hen that is suddenly staying in the hen house. She was fine this morning and I believe she laid. Now she isn't eating or drinking. She is crouched with her head down. I might not be too worried about this, but we had one that was out in the yard last week and appeared to be fine that morning. By that evening she started exhibiting the same symptoms and she was dead the next morning. The hens are 3-1/2 years old.