Hermits will need larger homes....either they find a empty one or take what they need from a snail!!!!Maybe even evict a crab from his and take it!!!Dang hermits are always fussing about their accomadations!!!
I recommend asking your lfs to throw in some extra shells that are larger when you buy your crabs. Thats what I did and they gave some extras to put on the substrate so when they are ready to move they have their pick!