Why Hermit Crabs Leave Their Shell?

When someone mentions a hermit crab, we can immediately associate it with a shell. This is, indeed, their safe mobile home as well as their protective armor. Shells also double as a sort of a hydration back-up, with plenty of water reserves on their inside.

That said, seeing a hermit without its shell can often make us wonder what brings to such an odd decision. Well, there can be several reasons why hermit crabs leave their shell, with some of them being completely normal and others being a warning sign.

To help you distinguish ones from the others here is all you need to know about “shell evacuation”.

Hermit Crab Leaving Shell

Below you can read about the most common reasons why hermit crabs evacuate their shell:

– Molting

Molting is certainly one of the most natural reasons that make a hermit crab temporarily homeless. In fact, during such a spectacular life phase, these creatures are not only leaving their shell, but also their exoskeleton.

Molting is how these creatures grow. Once they exit their shell, they will need to bury deep down in the substrate and stay there for a while. It is impossible to predict how long will such isolation last since this varies among individual hermits and their current body sizes.

Nonetheless, once they grow a new exoskeleton and decide to come out, they will begin their research for a new shell. Slightly larger and improved.

If you notice your hermit pet eating more than usual, spending more time in water pools and digging its way into the substrate, you can be almost sure that it is preparing to molt.

This is perfectly normal and you should not interfere other than assuring your pet is not being bothered.

– Temperature & Humidity

Inadequate environmental conditions are, sadly, quite frequent among disinformed first-time owners. These funny creatures require appropriate tropical temperatures to thrive, as well as high humidity levels to breathe through their modified gills.

When such requirements are not met, they will be forced to either bury themselves into the substrate or leave their shell. That does not mean that the issue is solved once they leave their armor, but it is more of a desperate cry for help.

Such an unpleasant situation is really simple to avoid by simply placing both a thermometer and a hygrometer in the middle of the enclosure. Try keeping the environmental conditions stable at all times, as hermit crabs are quite sensitive to such oscillations.

– Inadequate Shell

Hermit crabs are quite picky when it comes to the selection of their new shell, so please make sure to provide plenty of available choices for them to choose from. If they are forced to inhabit a too large or too small shell, or one which does not feature an adequate opening part, they will abandon it quite soon.

The simplest yet most effective way to avoid that is by always trying to find similar shells to their previous ones, but slightly larger. Also, avoid heavily colored shells.

– Dirty Shell

Being forced to live in a dirty shell is a perfectly understandable reason which brings hermit crabs to decide to be homeless instead.

This can happen both because new shells have been placed into their enclosure with no previous sanitation, but also because sand can sometimes find its way inside and harden. Such shells can become extremely uncomfortable for your pets to live in, so it is super-important to avoid such situations.

Firstly, make sure to always boil new shells before placing them into the tank. And once you do, simply spray them a couple of times with de-chlorinated saltwater.

Next, choosing the best type of substrate can avoid many unpleasant consequences. Instead of placing sand, try using coconut fiber instead. This is much softer but it also holds humidity better- two advantages in one decision.

– Breeding

When breeding, both the female and the male specimens will emerge either fully or partially from their shells.

This is necessary as the male needs to hold her lady partner with one claw, moving back and forth. You will easily realize if they are mating, as their stomachs will seem attached to each other.

– Disease or Parasite

Although hermit crabs are generally really healthy pets, they can often get sick due to poor maintenance. And usually, the most frequent reason for getting ill is because of parasite attacks. During such state, they will leave their shells, trying to escape from mites or flies or even fungus.

If your pet is affected, you will be able to notice visible signs such as external parasites across their body and shell, lethargic behavior, smelly odors or even multiple limbs being lost.

You will probably need to isolate your sick hermit and thoroughly clean the tank. However, if you are not sure of its health state, do not hesitate to ask your vet for guidance.

Can Hermit Crab Live Without Shell?

When finding themselves out of their shell, hermit crabs are extremely vulnerable to basically all external factors and drastically stressed out.

That is why, even if they can survive for a brief time during such sensitive phase, they will tend to die after a while.

How to Get a Hermit Crab Out of Its Shell?

Forcing your hermit crab out of its shell is always a terrible idea, so please avoid doing so. Instead, try gently picking it up and placing it on the open palm of your hand.

Encourage your pet to come out by softly talking to it and embrace yourself with a lot of patience. It will come out eventually, but it surely needs to feel safe around your presence first.

Wrapping Up

Hermit crabs are fragile little pets with their only protection being their own shells. Therefore, if they decide to leave those, there must be a perfectly good reason causing such behavior.

Breeding and molting are completely natural and normal activities and you should never worry about these.

However, inappropriate environmental conditions or a poor choice of substrate, as well as unsterile enclosures, can force these creatures outside their shells making them really, really stressed out. In such cases, they will require your help and extra care.

avatar Noah
I’m Noah, chief editor at VIVO Pets and the proud owner of a playful, energetic husky (Max). I’ve been a volunteer at Rex Animal Rescue for over 2 years. I love learning and writing about different animals that can be kept as pets. read more...

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