Mantis shrimp in there (or not?)

[justinl]

I can't imagine a mantis of any species/size that could survive for a month between feedings. Do you have any other mysterious vanishings? If ynot, Then I doubt it's a mantis. And even if it is, a snail a month isn't such a bad price to avoid tearing down your entire system in search of something that might not even be there (that would be a let down and a half )