The most important thing to remember when caring for a terrestrial hermit crab is that a healthy crab is a happy crab. Properly caring for your pet could result in up to twenty years of enjoyable companionship. A pet hermit crab requires very little maintenance, but what it does require is very important.
The first thing to do to care for a hermit crab is to set up an appropriate habitat. The small wire or plastic cages provided at boardwalks or pet stores won't work long-term. These animals need a lot of space to climb and move around, as they travel extensively in the wild. They are also avid climbers, so make sure your habitat has a lid to prevent escapes. A glass aquarium of at least ten gallons is sufficient.
The substrate, or the material at the bottom of the habitat, should consist of sand. You can use play sand, available at home improvement stores. Even better is sand purchased from a pet store that contains supplemental calcium. Be sure to provide objects for your hermit crab to climb on, such as drift wood, rocks, or a small piece of chicken wire.
It is also important to provide a large selection of empty shells. The shells should be larger than the one the crab is already in. Be sure to check the opening of the shell rather than the size of the entire shell. Shells that appear to be bigger may have a smaller opening than your crab’s current selection.
A pet hermit crab requires a high humidity level in order to breathe. The habitat should be misted with water daily in order to maintain humidity, especially in air conditioned and heated homes. Placing a humidifier near the cage is a great idea too. It is also helpful to keep a wet natural sea sponge in the habitat. In air conditioned rooms, you should supply a heat rock as well.
Hermit crabs also require fresh drinking water. Provide your pet with a shallow container of water that contains gravel or rocks to prevent the crab from drowning. Regular kitchen bowls are fine to use for drinking water, but pet supply stores usually carry water bowls made of rock that add aesthetic interest to the terrarium.
In the wild, hermit crabs are scavengers, so feeding your pet a variety of different foods will keep it healthy. Crackers, vegetables, and fruits are appropriate foods. You can also buy specially formulated food at a pet store to guarantee that your hermit crab is getting a balanced diet.
It is very important to provide foods that are high in calcium. Some hermit crabs enjoy snacking on egg shells, which meet this nutritional need. A combination of store-bought food and foods that you provide is the best way to keep your it healthy. Be sure to remove uneaten food to prevent mold and bugs.
A healthy hermit crab will grow larger and must shed its exoskeleton by molting about every six months. Many people think that their pet is dead when it is simply molting and dispose of the crab while it is still alive. A hermit crab will usually bury itself in the sand or hide under an object for days or weeks when it begins to molt. It must leave its shell to molt, and at that time it will not move and may appear to be dead. You can tell very easily whether your pet is molting or dead by smelling it, since a seemingly lifeless crab that is molting will not have an offensive odor.
It is important not to touch or handle a molting crab. Doing so could be life-threatening for the crab, because it takes a while for the new exoskeleton to harden. It is also critical not to remove the skin that is shed, because the crab needs to eat it to regain the calcium lost through molting. Calcium is what causes the exoskeleton to become hard. The best course of action is to leave your hermit crab alone until you see that it has become active again. You will also be able to notice the difference in color between the hardened and unhardened skin.