I purchased a clean-up crew (snails, cleaner clams, hermits, emerald crabs, coral banded shrimp, etc.) from this site 3 weeks ago. It was recommended that I isolate them for 3 weeks before moving them to my 125 gal display tank. As a rule of thumb, if they move they are alive and I will transfer them to the display tank. The two cleaner clams don't seem to move. I read they are nocturnal, but they seem to stay in exactly the same spot all the time. They are not open. How do I know if they are alive? I wonder if I should throw them out. A few of the hermits and snails don't seem to move either, but I'll watch them for a day or two. Any advice will be appreciated. Thanks.