As omnivores land hermit crabs can eat foods of both plant and animal matter. By purchasing from any number of online speciality stores even beginners can feed their crabs a lot of fresh or dried foods (Going Natural Beginner's List ). Crabs eat more when not consistently fed the same thing.
Many experienced owners feed a totally natural diet, but this requires a lot of variety (Hermit Crab Nutrition Table). There are retail sites that buy in volume and repackage organic foods in small amounts for the appetites of hermit crabs. This reduces the expense and potential waste of buying lots of different type of foods.
Owners can also grow their own plants and sprouts organically. People who purchase organic foods and who use sea salt (instead of table salt) can often feed the crabs table scraps. For whose who care to cook for their hermit crabs, there are many recipes online.
There are lists available online of what organic items can be fed at ( "Hermit Crab Cuisine" ) and what items should not be fed to hermit crabs. Organic worm castings (poop) will be eagerly consumed. (The idea that dairy is not acceptable has been proven to be a myth.)
The "do not feed" list contains natural insect repellents and pesticides, as well as toxic or "won't eat" items. The list includes things like bay leaves, cinnamon, dill, garlic, lemon, onion, rosemary, thyme, and table salt, so beware of feeding seasoned foods.
Unfortunately, picking a good commercial food can be difficult. There are many , including ethoxyquin and copper sulfate. Ethoxyquin is a preservative used on most fish that is not destined for human use. Since pet food companies do not add ethoxyquin themselves, they do not have to list it on the label!!
Any pelleted items fed to hermit crabs should be crushed first. Dry food can be left in the tank for 48 hours. Fresh foods should be put in at night and removed the next morning to reduce the chances of attracting biting mites. Putting foods in various areas of the tank (including some elevated areas) will give your pets some exercise.
Fresh foods can also be fed outside of the tank (not more than one hour). Just put sand on the bottom of a clean, plastic tub (one not exposed to chemicals or cleansers), then add both the food and the messy crabs. This is good for feeding broken, cooked chicken bones with some meat left. The crabs will love both the marrow and the meat. Pieces of raw or cooked fish can also be fed this way.