If you are going to get hermits, get really small ones or scarlet hermits. Blue legs are pretty good at wiping out snails for shells. Especially cerith or nassarius snails. Also, if you have hermits, be sure to have empty shells. It cuts down on the snail deaths. They always need bigger shells after they molt. I like the Mexican red leg hermits or the scarlets. They haven't messed with any of my snails. It's those stray blue legs though.