I lost 4 full grown hens during the day. I found them in their house. They had no noticeable marks. One hen had a small bald spot on it's breast. I couldn't find any broken bones. It looked as if they had just laid down and died. I do have snakes, rats, cats, raccoons, opossum, hawks, owls. During the day I have had dog, and hawk problems but nothing like this. One neighbor said it could be a posionous snake. Any ideals?