Hermit Crab Care Sheet



Hermit Crab, photo by DanTheBeastMan
Hermit Crab, photo by DanTheBeastMan
  • Scientific Name: Paguroidea
  • Lifespan: Approximately 20-30 years
  • Handling: Most hermit crabs are capable of being handled. However, use caution when doing so, as they do have pinchers that can get you.
  • Size: Approximately 2-6 inches
  • Care: Easy
  • Community: Yes, hermit crabs get along together and are quite social. They actually get lonely without companions. However, some species of hermit crabs need different types of housing environments which may cause a conflict.
  • Lifestyle: Nocturnal, active at night.


Tank size varies:

  • 1 hermit crab requires 5-10 gallon tank
  • 2 hermit crabs require a 10 gallon tank
  • 3 hermit crabs require a 15 gallon tank
  • 4 hermit crab require a 15-20 gallon tank

The rule is 1 hermit crab to about 5-8 gallons in a tank. This will allow most comfortable living.


Note: A lid is necessary on the tank enclosure to avoid escapes.


1) Hiding spots which may include coconut huts, log pieces, habba huts, and etc. This allows them to retreat to places when they want to sleep or even when they feel threatened. I would put multiple hiding spots throughout the enclosure if housing more than one hermit crab.


2) Climbing materials which may include pieces of wood, large rocks, and etc. They love to climb and will be busy all night doing it.


3) Three bowls. One for saltwater, one for freshwater, and one for food.


4) Extra shells. Each crab needs 4 extra shells (minimum) to allow them to switch into when growing out of their older one. These shells should be slightly larger than the shell that they are using now.

Lighting and Heating

Pacman frogs do not need a UVB bulb or any other type of special lighting. All they need is a source of heat through a regular house bulb.

Temperatures should be…

Day Time

75-80 °F is recommended. Consistent low temperatures can kill a hermit crab. Do not allow your hermit crabs to overheat next to a window, either. If they get too hot, they will die. Overheating causes irreversible damage and a slow, painful death. Signs of overheating are a musky smell and a discharge of brown liquid.

Night Time

No lights are necessary. 72-75 °F is recommended. If it is too cold to achieve this temperature without lights, I recommend using a heat emitter or a reptile infrared heat light. Make sure to check temps at night, to reassure the temps are good to avoid stress.


Hermit crabs are omnivores; therefore their diet must consist of both meat and plant matter. They require calcium, carotene, and antioxidants just like people do. To make sure your crabs get adequate carotene, supplement their diet with brightly colored vegetables, like corn and carrots.Meats may be offerred raw or lightly cooked with small amounts of vegetable oil. No salt or seasoning should be added to your meat, as it will harm your hermit crab(s). Freeze-dried foods such as shrimp and blood worms are also safe as long as they do not contain any preservatives. Ideally, fruits and vegetables should be organic; otherwise wash them thoroughly with de-chlorinated water.

Fresh food should be offered daily and should be switched out daily. Same foods over and over will bore your hermit crab(s) out. They like variety and need variety in food to thrive well.

Humidity and Hydration

Humidity levels should be between 75-90%. You can achieve these percentages by misting the hermit crabs enclosure twice daily; once in the morning and once again in the afternoon. If the levels are still not being reached, just mist a few more times throughout the day. Don’t mist too much, that your substrate turns into mud. You don’t want that happening. Hermit crabs have modified gills that allow them to breathe, but to be able to breathe, they need to breathe moistened air. Air that is too dry will actually dry out their gills, making it increasingly difficult to breathe until they finally end up suffocating. This is why it is extremely important the humidity stays above 75 percent at all times. But don’t over do it either. Too much humidity can cause health problems as well.


For hydration, your hermit crab(s)  will use the two water dishes to drink and hydrate from. The two water bowls must be present in the enclosure at all times. They should be big enough that your hermit crabs can submerge themselves, but set up in such a way that it is easy for your crab to get into and out of them. The first bowl which will be your fresh water container should hold spring water or de-chlorinated water. The second bowl which will be your saltwater container should be a mixture of de-chlorinated or spring water and a special aquarium salt-mix (regular table salt is not acceptable and will harm your hermit crab). We recommend putting these dishes in a low area of the habitat to mimic a shoreline, as hermit crabs would generally live near the ocean.Make sure to change out the water as necessary to avoid bacteria buildup and to make sure the water is clean.


People use different substrate and have different opinions. You should choose a substrate that is easy to clean and that will allow your hermit crabs to tunnel and burrow in it. The two preferred substrates are sand and coconut fiber substrate. You can purchase special terrarium sand or play sand. Coconut fiber substrate such as Eco Earth works well also, and is especially good for tunneling and burrowing. Many hermit crab owners elect to use a combination of the two. Avoid gravel, wood chips, or other substrates that are unsafe or do not allow them to dig. The amount of substrate that should be in your hermit crabs enclosure should be twice the height of your tallest hermit crab. This will allow enough substrate for your hermit crab(s) to burrow in. Make sure to keep the substrate damp to retain humidity in the crabitat. Make sure to clean out the substrate monthly to re-assure cleanness. 

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