I have a bunch of qhost shrimp in my cool water axolotl tank. They seem to pick apart the poo, maybe to see if anything came out undigested... they certainly don't clean up the poop piles though. Kinda just spread it around. I have fine white sand, little flow and relatively calm creatures in that tank, so I have a pretty good idea where the poo is. It stays put until I suck it out with a turkey baster
