A hermit crab can live up to an astounding 25 years! They begin about the size of a marble and can grow to be the size of a baseball. Hermit crabs are happiest and best-kept in pairs at the least, as they are actually quite social. They should not be kept in captivity with other animals, however, only other hermit crabs.
A glass terrarium is the most ideal container, minimum of 10 gallons. Keep the temperature no lower than 75°F with a consistent humidity around 70% . Substrate, such as a sand, play sand, or or shredded coconut fiber is ideal for the bottom of the enclosure. It should be deep enough that the crabs can bury, at least twice as deep as the size of your largest crab. Have both salt and freshwater available to your crabs, and also a wide selection of shells for them to choose from. It is also recommended to have branches or small logs for them to climb on.
You can feed your crabs any fresh or dried fruits and vegetables, whole grain foods, cooked egg, meat, and fish, and dried shrimp/plankton. Calcium powder or crushed cuttlebone is also recommended.