Hermit Crab Care

Hermit crabs – despite their less than friendly name – can be the perfect first pets for kids or companions for anyone interested in coming out of their shell and enjoying a new pet. But these crabs do need proper care or they may just get crabby with their new owners!

What Hermit Crabs Need

Before you bring a hermit crab home, you should know that it needs…

  • Adequate Tank Size: These crabs may be small, but they do grow and they are active. A 10-20 gallon tank is good for 1-3 crabs, and larger tanks can accommodate bigger groups of crabs and provide a more stimulating, enriching environment.

  • Comfortable Temperatures: These are tropical animals and need temperatures between 75-85 degrees. Unless you like a very warm home, this will require a good quality tank heater, and the tank should never be positioned near a vent or sunny window that could dramatically impact the temperature.

  • High Humidity: These crabs breathe through hardened gills and require high humidity – 75-85 percent relative humidity – for adequate oxygen intake. This means their tank will need to provide a tropical habitat with proper venting and moisture. Sponges and moss can help increase the humidity and keep hermit crabs healthy.

  • Clean Water: Hermit crabs need access to both fresh and salt water to balance the salinity of their shells, and water dishes will need to be relatively shallow to provide easy access. Water must be clean and free of chlorine and other chemicals, because hermit crabs are highly susceptible to contamination.

  • Proper Flooring: Digging is not just a favorite pastime of hermit crabs, it is essential for when they molt their shells or need to escape from stress. The tank's substrate needs to be 2-3 times as deep as the largest crab's size to provide adequate digging space. Sand, coconut fiber and moss are all popular hermit crab flooring options.

  • Plants: Fresh, healthy plants are a good addition to any hermit crab habitat, and varieties such as natural bamboo (not "lucky" bamboo, which can be toxic), air plants and spider plants are all good choices for décor, air freshening and the occasional snack for a curious hermit crab.

  • Hiding Spaces: In addition to room to dig, hermit crabs need a cozy niche for hiding when they feel threatened or stressed. The space needs to be small enough for them to feel secure, but large enough so they don't get stuck. Half a coconut shell, a hollow log section or a broken clay pot are all good choices.

  • Varied Diet: Hermit crabs are omnivores and need a varied diet for the proper nutrition. Crab pellets make a good basic diet, but should be supplemented with fresh fruits and vegetables, bits of raw meat, oyster shells, brine shrimp, krill and other foods.

  • New Shells: A healthy, growing hermit crab will need a new shell regularly, and it is best to provide at least 2-3 options that are 10-15 percent larger than the crab's current shell. They can be picky about their new accommodations, and unused shells should be swapped regularly to offer more choices.

  • Toys: Hermit crabs can be very curious and love to investigate new objects, especially anything they can climb on. Rocks, logs and stumps are all good options for hermit crab enrichment, but be sure the toys are arranged safely so crabs will not fall or escape.

  • Company: Hermit crabs aren't really hermits, and in fact they love having companions. Keeping multiple crabs can satisfy their social natures, and they should be handled regularly (and gently!) to get used to their human companions as well.

With proper care, hermit crabs can be fun, happy pets to enjoy, ideal for all ages and perfect for small spaces and less experienced pet owners.