In their natural environment, hermit crabs eat decaying wood, grasses, plants, fallen fruit and things washed up on shore from the tide. Land hermit crabs are omnivores, meaning they eat both plant and animal matter.
Captive hermit crabs should have a diet based on balanced commercial food supplemented with a variety of fresh foods and treats. According to PawNation, hermit crabs enjoy baby food, particularly fruit such as apples, bananas, mango fruit, guava fruit, sweet corn casserole, sweet potatoes and applesauce. Foods such as walnuts, peanut butter, sunflower petals, honey, oatmeal and wheat germ also offer a nice change to fruits and vegetables.
Sardines, blood worms and meal worms are also suitable. However, make sure the meat does not contain any spices or table salt. Hermit crabs are also extremely sensitive to flowers treated with fertilizers or pesticides and processed food with excess sugar and table salt.
Commercial diets, which come in canned and pellet form, are available at pet stores and through online manufacturers. According to About.com, pellet foods can be fed once a day and should be crushed or moistened for smaller crabs. Uneaten food, including the commercial foods, should be removed daily.