General Information
Despite their misleading name, hermit crabs are very peaceful, curious, sociable creatures. Hermit crabs live in large colonies throughout the Caribbean Islands and in southern Florida. They have ten legs, though only a few are normally visible. Hermit crabs only leave their shells to move into a larger or better fitting shell.
 
The hermit crab’s front left leg has a large purplish pincer, which it uses for climbing and defense. This pincer also blocks the entrance to its shell when it’s frightened. Its smaller right front claw is generally orange or brownish, and is used for eating and climbing.
 
Hermit crabs are most active at night. Don’t be disappointed if your new pet doesn’t explore or eat a lot during the day. As it becomes more comfortable with its new home, and with you, it will become more active for longer periods of time.
 
The Tank
Hermit crabs will live happily in either glass or plastic tanks. Most breeders recommend using special calcium-enhanced sand, which comes in a variety of colors, in the bottom of your tank. This sand is quite expensive, must be cleaned regularly, and should be replaced every month.  Aquarium gravel is an inexpensive alternative, and can be washed and reused indefinitely.  Shredded coconut bark is also a fine substrate, being easy to clean.  Its further advantage is that it will not turn moldy when wet.
 
Hermit crabs are very curious, and love to explore.  Be sure to place a different rock, stick, or shell in your hermit crab's tank every week. Your pet will have fun exploring everything, and you’ll have fun watching it.
 
Remember to keep your tank’s lid securely fastened!  Hermit crabs love to climb, and can easily escape an open enclosure.  If your hermit crab does escape, search first in dark, cool corners and crevices, and also in high areas like curtains.
 
Food and Water
Hermit crabs will eat almost anything. In the wild, they scavenge food on the seashore, and will eat everything from dead fish to coconut scraps. Commercially prepared food can be purchased at most pet stores, and will keep your hermit crab strong and healthy.  But like all creatures, hermit crabs love variety.  Give your hermit crab small bits of bread, crackers, lettuce, peanut butter, apples and other fruits, coconut, grapes, oatmeal, cornmeal, and dry scraps of fish or chicken as treats. (Remember to remove any uneaten scraps before they spoil.)  You can also teach your hermit crab to eat from your hand.
 
Hermit crabs live near water, and need a steady supply of fresh water.  They will often wade around their water bowl for extended periods of time.  But they cannot swim well.  So never put a deep water bowl in your hermit crab’s tank.  If it cannot climb back out, it will drown.
 
If you use a sponge instead of a water bowl, keep the sponge moist. Your hermit crab will climb on it, and drink directly from the sponge.
 
The Shell
Never try to pull a hermit crab from its shell.  It will not leave until it is ready, and you will tear it into pieces if you pull hard.  Always keep a few extra (larger) shells in your tank.  When your hermit crab outgrows its existing shell, it will move into the new shell it likes best.  It doesn’t matter whether the new shell is painted, decorated with gems, or left plain.  Your hermit crab will only care about whether its shell fits properly.
 
Please Note:  Despite the hermit crab's popularity as a tourist souvenir purchase, it should NOT be considered a "throw-away pet."  Hermit crabs, if properly cared for, can live for many years.  Due to their popularity, native beaches are rapidly becoming over-harvested, and in many areas, hermit crabs are becoming endangered or extinct.  Please think carefully before purchasing one of these curious, intelligent crustaceans.  They are a decades-long commitment, just like a reptile, parrot, or other long-lived exotic pet.