I have had a white and black aquatic snails in a 2 gallon tank with a betta fish for a little over 2 months. I found a baby snail in the tank once while I was cleaning it out that was floating, I left it be but then it disappeared...I assumed my fish ate it. Today I found another baby at the bottom of the tank under the rocks. I moved the fish into a bowl (to clean out the tank) and the snails along with the baby into another bowl. I am fearful to put him back in the tank with the fish!!! I have been watching the baby for several hours and have not seen it move even the smallest bit. It is laying back down on the bottom of the bowl. How can I tell if it is alive or dead