I usually fill my fish feeder and how long feeding times are and can usually come pretty close to knowing when it needs to be refilled. Last time I ran out a lot quicker than I have in the past. I set up a camera there and caught the thieves. One racoon will reach the feeder and spin the spin plate while his buddies enjoy the work. I'm trying to fatten up bluegill, not racoons.
That's why I like Texas Hunter directional fish feeders. They are coon proof. (unless they learn how to undo the latch on top of the feeder. Then a small carabiner through the latch will solve that problem.)
Lake8, I have a similar directional feeder and had to fabricate a chute so the coons couldn't reach in. They get what little food remains in the chute each night, but aren't able to empty the feeder.