Hermit crabs spend their lives within their conches. Aside from occasionally leaving to molt, cool down in extreme temperatures, or upgrade shells, hermit crabs never leave the safety of their homes.
That can leave you puzzled when a hermit crab abandons its shell, wanders off to a different part of the tank, and suddenly dies without explanation.
Most hermit crabs will die within their shells, as this is the safest, most comfortable place. If it seems that a hermit crawled out of its shell to perish, it’s just a coincidence.
Do Hermit Crabs Leave Their Shell to Die?
Hermit crabs don’t vacate their shell because they know death is near. Many hermit crabs prefer to stay inside their shells when ill or injured for these reasons:
- Comforting place
- Keeps them hydrated
- Protection from the elements
- Protection from predators
- Safety from other hermit crabs
The shell is the best location when a hermit crab tries to heal from an injury or illness. However, if it can’t overcome the effects on its body, it can die inside its shell.
This leaves most owners to clean the shell once their hermit crab has died. In the wild, it would decompose inside, or other hermit crabs would drag out the body to claim the shell.
Hermit Crab Left Shell And Died
Many animals seem to sense when they’re about to die and exhibit certain behaviors in response.
If a hermit crab perished after leaving its shell, it’s logical to assume it did the same. It left the shell so it could die in peace, maybe even preserving the shell for another hermit.
However, hermit crabs show no obvious behaviors when approaching death, aside from the symptoms of disease or illness. They won’t act differently or prepare themselves for the end.
If a hermit crab left its shell and died, it’s likely because:
Sick or Injured
Hermit crabs that are extremely sick or have lost a limb may be unable to keep themselves inside their shells, leading to them falling out when they move.
Once the hermit has fallen out, it may be unable to get back into the shell.
It seems like it purposefully vacated the shell and refused to return. In truth, it wanted to but couldn’t. It may have succumbed to an outside threat, if not the original injury or illness, shortly after.
The fact that a hermit crab left its shell was a byproduct, not a sign of pending death.
Harmed While Changing Shells
Once a hermit crab outgrows its old shell, it’ll seek to find a larger replacement. This will require it to leave its shell and find a superior alternative. Hermit crabs steal shells and fight over them.
Different species prefer different types of shells to reside in. If you don’t have enough options, the hermits may feel their choices are limited and fight.
Things might have turned nasty if a hermit made a switch and got confronted by another hermit.
Dehydrated
If a hermit crab lost its shell to a rival or left for another reason and couldn’t get back inside, it might have died due to the lack of a shell.
According to the Journal of Experimental Marine Biology and Ecology, hermit crabs need 50% more oxygen than hermit crabs without shells. Also, they rely on humidity to absorb oxygen.
Hermit crabs maintain the right balance by moistening the inside of their shells. If the hermit crab was out of its shell and couldn’t get back inside, it might have died.
Better Shell
Hermit crabs use their shells for protection, so they’ll hide inside if they feel threatened.
The Journal of Experimental Marine Biology and Ecology found that hermit crabs in sub-optimal shells often abandon their homes, especially in times of danger.
This danger could directly threaten its life, such as illness or being trapped under debris. Also, it may feel so stressed that it thinks it’s in danger.
Hermit crabs can’t survive without a shell for too long because it leaves them overly exposed to their surroundings, dries them out, and makes them lethargic.
If a hermit can’t successfully switch to a better option, it could die without a quality shell to protect it.
Stressed
Due to stress, the hermit crab may have vacated its shell and failed to discover a new one. Despite their seemingly hardy nature, hermit crabs stress out easily.
Something as simple as a change in humidity or temperature may cause the hermit to leave its shell. Once outside, the stress could have made it sick or inhibited its ability to find a new shell.
Unsafe Shell
A sick hermit crab will vacate its shell if it feels it has been contaminated.
A hermit crab might have mites, debris, or other particles lodged between its soft abdomen and the shell. Also, it may have developed a fungal or bacterial infection that led to skin disease.
Failed Molt
Molting is difficult for hermit crabs, so some will temporarily leave their shells and bury themselves in the sand to begin the process.
Throughout this ordeal, the hermit may be vulnerable to:
- Attacks from other hermit crabs
- Cave-ins from the sand
- Environmental changes
If the hermit leaves its shell, runs away to bury itself, and ends up dead, that’s usually the cause.
Do Hermit Crabs Die Inside Their Shell?
Most hermit crabs will die within their shell, as there’s no reason to brave the scary, outside world if it knows it’s sick or injured.
Whatever the cause of death, a hermit crab will likely attempt to overcome it within the safety of its shell. If it fails, the body will remain inside until:
- It decomposes
- Another hermit crab pulls it out
- You remove the body
A dead hermit crab will take on an unpleasant, fishy odor. You’ll be able to smell it if you get anywhere near its enclosure, which is often the first sign that a hermit crab has died.
How To Get A Dead Hermit Crab Out of Its Shell
If a hermit crab dies in its shell, you can dispose of the body, shell and all, or fish them out of the shell. The latter option is preferred, as the living members of the colony will use the shell.
There are two ways of getting the deceased hermit out of its shell:
Insects To Eat The Carcass
Find an anthill or other patch of soil with insect life. Bury the hermit crab in this anthill or patch of dirt so the insects will clean out the old carcass. This method is thorough and leaves little odor behind.
Freeze The Shell
Freeze and thaw the shell at least twice for several hours each. The hermit crab’s body will become stiff and easy to remove with a toothpick, tweezers, or another tool.
Clean the shell afterward to kill any lingering bacteria. Sterilizing the old shell in a pot of boiling water (not tap water) for 15 to 20 minutes is a good cleaning method.
Hermit crabs will stay in their shells to die. If you find a hermit roaming free, it hasn’t figured out that the end is near. Instead, it could be molting or searching for a bigger shell.
