2 weeks ago I was working in the garden, heard a noise behind me and turned around to see a rat snake wrapped around a rat sticking out of a small space in my eves! It was about a 5' snake and a pretty big rat and I have no idea how either one of them got up there! Racoons and rats can climb really well; make your coop as secure as possible and hope for the best. I still like the idea of putting dog hair around the coop to discourage these kind of predators.