Crab stole snail shell!

So far my hermits are doin 90% of the work load. Snails are on glass and the hermits have cleaned my rock and and bed amazingly. Al my diatoms are gone and the loose stuff on the rocks is picked clean. Well see how they do. I havent found anymore empty shells and there is only one hermit in a snail shell. I do need to get a peppermint shrimp. I have a few small apstasia i wanna get cleared