Molting is when a hermit crab sheds its exoskeleton to grow. This is a natural and essential process that happens several times throughout their lives. During this time, crabs burrow underground for privacy, safety, and proper exoskeleton hardening.
Decreased activity or hiding more than usual
Dull or ashy-colored exoskeleton
Cloudy or bluish eyes
Digging frantically before disappearing underground
Provide deep, moist substrate (at least 6 inches) for safe burrowing.
Leave molting crabs alone – disturbing them can be fatal.
Ensure proper humidity (70-80%) so they don’t dehydrate.
Provide calcium-rich foods before a molt to help shell regrowth.
Never dig up a buried crab! – They are highly vulnerable during molting.
Don't separate them unless necessary. Molting in the main tank is normal.
Avoid handling – Their new exoskeleton is soft and fragile.
SURFACE MOLTS
What It Means:
Molting usually happens underground, but sometimes crabs molting on the surface were unable to dig due to stress, lack of deep substrate, or improper humidity.
How to Protect a Surface Molter:
DO NOT Move Them! – Touching a molting crab can cause serious injury.
Isolate Them – Use a plastic bottle with air holes or a cut plastic container to create a protective barrier.
Increase Humidity – Keep levels above 80% to prevent dehydration.
Leave Exoskeleton Intact – The crab will eat its old exoskeleton to regain nutrients.
If tankmates are disturbing the molting crab, you may need to carefully move the other crabs to a temporary tank.