How to Tell What Kind of Hermit Crab You Have

Hermit crabs are naturally active beach dwellers that enjoy the company of other crabs, switching shells and space to wander. Many experts believe it is not possible to figure out whether your hermit crabs are male or female, but the truth is though it is difficult, it is not impossible. A comfortable hermit crab allows you to see the gonopores on a female or the spermatophores on a male, but helping them feel that comfort is not always easy, even with the right techniques.

Things You'll Need

  • Dechlorinated water
  • Jar lid
  • Glass pebbles
  • Towel
  • Shoe box
  • Paper towel
Show More

Instructions

    • 1

      Leave tap water out overnight to dechlorinate it and allow it to come to room temperature.

    • 2

      Prepare a bath for the hermit crab. Place a half inch of dechlorinated water into a jar lid with a few glass pebbles and set it out. There is some debate about whether bathing is necessary for normal care, but there are times when it is quite helpful. You want to bathe hermit crabs that just came from the store or just molted. A hermit crab that just came from the store does not smell the same as the others and they all appreciate it if you bathe it to change that. A crab that has freshly molted smells like old exoskeleton and other crabs think it smells like something good to eat. Bathing it removes that smell. It also provides you with an opportunity to find out its sex.

    • 3

      Place the hermit crab in your hand and set your hand next to the jar lid. Allow the crab to walk off your hand into the lid itself. If it is hesitant to move off your hand, gently pick it up and place it in the lid so the water can go into its shell.

    • 4

      Remove the hermit crab from the bath after about a minute and tip the shell to drain the water out. Use a towel to wipe off the shell and place the crab in a shoe box lined with a paper towel.

    • 5

      Observe your hermit crab. They get very active after a bath, and if it is comfortable enough, it may stay far enough out of its shell to let you see what kind it is. Allow the crab to come out of the shoe box and crawl around on your hands.

    • 6

      Pick your hermit crab up by its shell slowly and gently and turn it over. If you see tiny dots under the fifth pair of legs below where they meet the crab's body, those are gonophores and it is a female. If you see tiny fuzzy legs, and no dots, those are spermaphores and it is a male.