The hermit crabs is one of the most essential tools for any saltwater aquarium. They wander around the tank cleaning up uneaten fish food, picking through detritus, and eating algae off of the rocks and sand. Unfortunately, these cleaners don’t always play nice, especially when it comes to snails. Because hermit crabs have a soft and unprotected abdomen, they use shells and other hard objects as protection. As the hermits grow, they quickly become too large for their homes, needing to replace them with more spacious digs. This means vulnerable snails are at risk, and the crustaceans will jump at any chance for an easy meal and new shell. Because of these reasons, many hobbyists refuse to own hermit crabs, favoring strictly herbivorous snails instead. I personally feel hermits are too important to completely ditch, so I purchase those species which stay small and predominately feed on algae and detritus. These include the blue leg and scarlet reef hermit crabs, along with a handful of others. I also keep the crabs in low numbers, tossing in a couple of extra shells for the hermits to fight over.