So I went to Petsmart today, and I saw a tank that must have been a bit larger than 5 gallons, and it had a bunch of glofish, and about 10-15 Gold mystery snails, which I am interested in. But as I watched them for a few minutes, not one of them moved, and two of them were upside down, with their foot visible and no movement. One of the upside down snails was near the edge and still didn't move when I tapped the glass. Is this normal behavior? could they have been dead?