For anybody reading this without the bat clues, the rest of the list is distinguishable by what you find at dawn. Feeder tipped or on the ground with the ports prised out and muddy prints on the railing is raccoons. Bent poles, a crushed or missing feeder and an obvious mess is a bear, and that one means bringing feeders in every single night without exception.
Raccoons you can beat with a thin wire away from railings and trees, or a baffle on a pole.