Hermit Crabs aren't fussy eaters. They're omnivorous and they're scavengers. They'll eat practically anything. If that 'anything' is good for them well, that's another question. Hermit Crabs have been observed eating fruit (mangos, papaya and coconuts are foods from their natural habitat) fish, nuts, seeds, decayed wood, leaves, plants, cereals, grains, grass, and anything found on the beach washed ashore by the tide. I've even read somewhere that Hermit Crabs eat poop. (Ok, that sounds horrendous so the correct term is 'organic worm castings' which is actually a special treat for your Hermit Crab as it is filled with vitamins and minerals and is primarily used as a natural organic fertilizer.)
The nutritional requirements of Hermit Crabs are not fully known but what we do know is this - they require calcium, carotene and antioxidants (just like we do!)
Minus the carotene and their shells fade from an eye-popping reddish orange to a blah tan. Feeding them corn, carrots and other brightly colored veggies will remedy this shell fading dilemma.
So what should hermit crabs eat? Think of all the good, healthy foods you should be eating and that's what your hermit crabs should eat! Fresh fruits and vegetables. Meat, fish, nuts, etc. Foods with zero processing.
Hermit Crabs also like foods rich in tannin like tree bark and oak leaves (after washing and drying them) because hermit crabs like crunchy but not necessarily clean snacks - that's a human requirement.
Commercial crab food may not be the best food for hermit crabs, especially if it contains copper sulfate or anything unfamiliar or unnatural except for 'tocopherols' because they're natural preservatives from the vitamin E family found in nuts, fish vegetable oils and leafy green vegetables.
You should be able to find all the food you need for your hermit crabs at your local grocery store or farmers market.
Hermit Crabs are creatures of variety when it comes to meal time. They like different foods for each meal they have. So mix it up a bit for them and keep your hermit crabs happy.
If you give them meat, be certain it has no sauce or butter on it or it could make them sick. They are bone pickers and like picking meat off the bone and it doesn't matter what condition the meat is in.
Dead, steamed shrimp tails or any crustacean will be a good dinner for your hermit crab. Place the meat into their enclosure in the evening and remove in the morning to discourage insects.
Hermit Crabs also will eat junk food like pretzels, corn chips, and sweetened cereals. They may like these foods but they're definitely not good for them. Instead, consider these wholesome treats found at your local pet store. Some are: escargot, frozen fruit, iguana food (plant based), seaweed, sun dried shrimp, brine shrimp minus the salt water, plankton, and fish flakes.
Most of this blog refers to the feeding of land hermit crabs but it can also be applied to the saltwater aquarium hermit crab you may have purchased to aid you in the clean up of your aquarium. If so, you can expect your hermit crab to eat the algae from your aquarium as well as debris, dead fish, fecal matter and even one of their own buddies who have passed away (hermit crabs are proven cannibals.)
Just remember, a healthy, happy hermit crab adds up to all the good food it eats (minus the preservatives!)
By Tom Matteo