How do you  create a habitat for hermit crabs?
 Make sure you get the right size of tank. A ten or twenty gallon tank is good for two to four small hermits. A twenty to forty gallon tank is good for a dozen small or three to four large hermits. The hermit crabs you’re most likely to have need a warm damp habitat, with a temperature of about 75 to 85 degrees Fahrenheit and a relative humidity of about 75 percent. Use a hygrometer to monitor the humidity and a thermometer for temperature. You should also place extra shells around the habitat for the hermit crabs to change into. There should be at least three shells per hermit crab, and the shells should be at least as big as or slightly larger than the crab's current shell. 