Possum it is!Very kind hearted of you not to ill it.The problem is that they are getting in!Dont let it happen!If there is a hole,if there is a tear if there is any kind of entry way fix it!If you have small gaps put plywood over them.If you can see lite in your coop,fix it.if you free range and are loosing your birds then your fighting a loosing battle to begin with.
