Scats will not eat poop and neither will any other animal. Some fish, like scats, will scavenge through detritis to consume anything that hasn't been metabolized already. In the process of scavenging, they will break up/stir up that detritis so it can be more easily picked up by the filter. The same goes for burrowing snails, brittle stars, etc.
Keep a healthy current running across the bottom of the tank that directs loose surface waste toward the filter intake. That will help a bit.