I placed a nassarious snail in my 55 gal tank about a week ago and I havent seen him since. He tried to go up the wall of the tank, but I placed him back down in the substrate, then he burried himself and I havent seen him since. At the pet store, they were very active and turning the substrate over. I trieb to entice him to come out like they did at the lfs, by placing some krill on the bottom. I dont want to disturb, all of the substrate, searching for him and digging stuff up. Any thoughts?