Apparently The Raccoons are using the roof as their loo. Nice. There's no way for them to get into the attic, so that's good. They're removing all that poo from the loo and then will treat the roof with some stuff they won't like. He said, interestingly, that it's rare for them to be in a pack like that and that they see that happen when someone in the neighborhood is feeding them. If it's true, I'd best not find out who that is.