Signs of a Dead Hermit Crab

Land hermit crabs are popular pets, but they need special care. Many people do not learn how to care for their hermit crab correctly and end up with either a sick or dead pet. Hermit crabs are nocturnal, which means they may roam all night, but sit very still during the day. This does not mean they are dead; they can lie in a single spot sleeping for hours and sometimes even go an entire day without moving, especially if they are sick. They also have molting seasons where they can disappear for a month or more. To assess a hermit crab's condition, one must first understand the way they live to know the difference between life and death.

  1. A Molting Land Crab

    • A molting crab may disappear under the sand.

      Molting is a growth process for the crab in which it sheds its old exoskeleton and grows a new one, possibly several times a year. The shedding exoskeleton can make the crab appear limp or dead as it comes off. Crabs will dig down into the sand or substrate until completely covered if possible; but in shallow sand, they will dig down enough to cover their body, leaving the shell exposed above. The crab will not move at all for at least one to two months. This may make the crab appear dead, but it is not. If the crab does not reappear after nine weeks, you may have to gently check on it, but do not automatically assume it is dead without checking.

    A Stressed Crab

    • A hermit crab may escape its shell under stress.

      A crab that is feeling stress from lack of moisture, too much heat or anything else will bury itself just as it does when molting, returning to its underground hideout, which can also happen after a molt has ended. It may even leave its shell behind when it does so. If the crab disappears for a long period, smooth the sand above and watch for tracks in the next few days to see if the hermit crab has come up in the night. It often returns to its exact position, making it difficult to be sure by just looking. Again, non-movement does not always mean death.

    Past Symptoms of Illness

    • A dead hermit crab may be curled up outside its shell.

      Before a hermit crab dies, you'll often see signs of illness or heavy stress. One or more of these could lead to the hermit crab's death. A crab can begin to lose multiple legs and/or a pincher. It may shed its shell and curl up exposed in its enclosure, leaving it unprotected. While these are signs of a lack of water or a dirty shell, when not rectified the crab dies. The crab may also quit eating fond foods, ignoring them completely before death.

    Overt Signs of Death

    • Once a crab has died, its body will slowly begin to dry and deteriorate. Hermit crabs need to be damp to survive. If a crab has not gone to the water at all, it is either dead or near death. The body will loosen from the shell and droop much as if it were molting. Its antennae will not move even when touched; and when moved, the crab may fall completely out of the shell and remain inactive after the fall. The final sign is the smell of dead fish in the tank, which signifies a sure death.