Okay... it all happened too quick for a picture but I just happened to walk in the room and caught my cleaner shrimp prying one of my new nerites off the glass, then he flipped it over and was just starting to dig into the shell. I moved in and shooed him away and moved the snail to the refugium. Resourceful little critters... I know the bristle worm population has cut back because of them but had no idea they were going for snails.