I have a big Nerite snail that seems to have been looking for a way out of the tank since I got him. He finds all of the gaps in the top of my biocube, ive found him in the pump chamber, sitting on top of the filter, and in the refugium chamber. I don't know how he has gotten to some of these places. A few days ago I couldn't find him at all. Figured he might be in the rock rubble in the refuguim. Did my water change today and cleaned everything out looking for him. He was no where in the tank. As I was cleaning up some water that spashed onto the floor, I found him under the chair about 2 feet away from the tank. He has most likely been out of the water for a few days. He dosen't smell and his trapdoor is closed. Any chance he could still be alive?