All of my neighbours' chickens got taken by foxes last week. I did tell them that they shouldn't leave them in a pallett-pen outside at night surrounded by chicken wire that was not dug in, even on a hard old gravel driveway... the foxes dug in through the gravel and probably spent a hour or so coming back and clearing out the lot. A racoon probably got in on the act too - we found a paw print!