Most of you have already heard it, that nerites can crawl out of fish tanks. I knew it too but I never really thought of it as a big issue up until today. One of my tracked nerites went missing a few weeks ago. I searched every corner of the tank but was not able to find it and just concluded that it died in some unseen cranny of the tank. Today I was cleaning around the tank and saw something wedged between the outlet splitter and the tank stand. It was a nerite snail. The snail must have managed to overcome the rim of the tank, dropped 4 ft. To the ground, continued crawling for a foot and then lay there for two weeks before I found it! Fortunately the snail survived the two weeks out of water. I will commence snail-proofing the tank immediately...