I had a hen die in the coop a couple of days ago. since then the other 3 hens have not returned to roost at night. They will go into the coop to eat and drink but do not hang around and have not gone into the roost where the egg boxes are or to roost at night, I have found one egg in the garden. A person on another forum on this site suggested that I check for a predator in the coop, like mice or a snake. I recently added grass clippings to the bedding in the run, which as I think about it would have chopped up black walnuts. There is also a downed walnut tree near the coop with piles of wood and saw dust from cutting the tree and logs. I know that this can't be good for the birds. and may have been the cause of death of the hen. It would not explain the behavior of the other hens. Any thoughts? In the meantime I am going to clean out the entire house.