Food and Water
Hermit Crabs are omnivorous scavengers who like variety in their diet. Hermit crab food, extra protein and vegetables, fresh water and salt water will help ensure they thrive in your crabitat.
A good complete hermit crab food should be available in the cage at all times. This will ensure that your crab has the proper vitamins and minerals that they need to survive. Hermit crab food comes in many consistencies from powder to large, hard pellets. A good rule of thumb is small, soft food for tiny crabs. Some manufactures recommend moistening their food. A food processor can also be used to change the consistency of large pellets to make them easier for the crabs to eat and will make your food go further.
Supplement with fresh produce and protein. Hermit crabs are omnivorous scavengers and like variety in their diet. It is always a good idea to give them additional fresh items in their food dish.
Just as humans have individual taste preferences, you will discover that your crabs do too. Experiment with a wide variety of foods to discover what your crabs like. Things like scrambled eggs, sardines, plain popcorn, even tofu are foods that hermit crabs may find enticing. The important thing is to give your crabs a variety from which to choose in addition to readily available commercial hermit crab foods.
Land hermit crabs seem to have a "sweet tooth" and prefer baby food flavors such as:
Apples & Bananas
Apples & Pears
Apples, Mango & Kiwi
Sweet Corn Casserole
Sweet Potatoes & Apples
Guava Fruit Dessert
Mango Fruit Dessert
Papaya Fruit Dessert
These can be fed by hand using The Hermit Crab Patch "Hermit Crab Feeder Spoon" or by placing a small amount in a dish for crabs to eat by themselves.
Another very important aspect in keeping pet hermit crabs alive is to provide a bowl of fresh water AND a bowl of ocean salt (not table salt) water in their cage at all times. Each bowl should be big enough for your largest crab to climb in to. If smaller crabs within the cage might have a challenge getting in and out of the water dishes, a small natural sea sponge can be placed into each dish to act as a safety bridge to prevent drowning. Hermit crabs use the water to drink, bathe and replenish their shell water (extra water they carry within the back of their shell). By providing both fresh and salt water you are letting the crab decide for themselves what they need.
Chlorine found in tap water is harmful to hermit crabs. In order to make tap water safe, dechlorinator drops can be used to remove Chlorine. Another alternative is to use bottled water for your hermit crabs fresh water supply and also use it to mix with aquarium salt such as Instant Ocean or Hermit Crab Soaking Salt to make salt water. Do not use table salt, it contains iodine which can be harmful to crabs. For crab owners that have well water, I still often recommend using bottled water. Some wells use a salt softening system or have higher levels of minerals. When mixed with the additional minerals in aquarium salt an unknown and possibly unsafe level of salt and minerals could result.
Shell water is important to a hermit crab. They use the shell water to hydrate their gills and will regulate its salinity (osmoregulation) based on their needs by switching between the fresh and saltwater dish. It is important that they have access to both fresh and salt water at all times. Hermit crabs preparing to molt will spend a lot of time soaking in both water dishes, storing water which will be used to enable them to build up hydrostatic pressure to swell and break open their exoskeleton during molting and also to survive on while buried.
By providing both fresh and salt water dishes which are deep enough for crabs to get into, the crabs will be able to bathe themselves as they do in nature, eliminating the need for hermit crab owners to do this for them. Of course if a crab has mites, it is a good idea to rinse the crab well by turning on lukewarm water and directing the water into the crabs shell several days in a row until floating mites are no longer seen on the water surface. Other than rinsing for mites, I believe that owners should let hermit crabs bathe themselves so that the crab's shell water salinity remains undisturbed.
Since calcium is an important component of a hermit crabs exoskeleton, it's a good idea to provide additional calcium for your hermit crabs. If you have beach sand as a substrate in your crabitat, crabs will eat bits of seashell as a calcium source. They will also benefit from the natural sea salt present in beach sand. Calcium can also be provided by sprinkling Calci-sand which is found in most pet shops or crushed oyster shell on the top of your substrate for crabs to eat. Introducing a cuttle bone, sea cookies or sand dollars into their environment can be an effective means of offering additional calcium to hermit crabs as well.
One of our most popular supplements with hermit crabs is our "Organic Soil / Diet Supplement" found exclusively at The Hermit Crab Patch. We learned of this amazing natural supplement almost accidentally from friends of ours that own a worm farm. When they gave us a sample to try, we were amazed at how all of the hermit crabs responded! The dish was packed with crabs and the bowl was nearly empty after 1 night of dining! We decided to carry the product and began offering free samples to customers to try. The responses that we received were confirmation that our experience wasn't unique...hermit crabs couldn't get enough of this stuff. Customers confirmed that their crabs were barely eating their "hermit crab food" and instead were spending all of their time dining on the Soil Supplement. This product is very similar to what hermit crabs in nature often eat, so it's not surprising that they love it and it's packed with vitamins and minerals.