I saw a large slug like creature on the glass last night sucking the life out of one of the snails in the tank..I turned on the light to capture it but it retreated very quickly into the rocks i don't know what it is but i do know i have to catch it.
Naw. Sometimes you might want to thin the herd a bit for asthetic reasons, but they're great little snails that graze on algae and surface films, and they reproduce pretty quickly.