Are Hermit Crabs Out Of Shell Danger?

Hermit crabs can be a great pet for children, however, this tiny creature requires an enormous amount of maintenance. Since they prefer to be in colonies, should you decide to keep several hermit crabs, and the bigger tank required to recreate their natural environment could consume a significant amount of space?

In addition, there is the risk of aggression, stress, and infections–all of which contribute to “shell evacuation”–and suddenly, a child’s pet becomes the responsibility of a parent.

Shell Evacuation in Hermit Crabs (Hermit Crabs Out of Shell)

Finding that you have a hermit crab without shells isn’t necessarily a sign that something isn’t quite right. Shell evacuation is a typical component of the development of hermit crabs.

Because the snails “borrow” a snail shell to live in, when they get bigger, this means shedding their exoskeleton as well as regularly changing to a bigger snail shell.

Alongside shell evacuation comes the work of a detective as well as a caretaker. It’s your responsibility to figure out the reason for this and make sure that your crab has an ideal new home in the shortest time possible.

What Is Shell Evacuation?

Shell evacuation occurs when your crab must “trade up” both its housing as well as its exoskeleton for the purpose of being able to fit greater body dimensions. It will remove the current shell to search for an appropriate one.

However, not all people who leave vessels are molting. Stress, uncomfortable surroundings, an unsuitable shell (too big and small, or just excessively heavy), and even unwelcome company could be the cause for hermit crabs to escape their shell. In this case, your crab that is homeless suddenly is exposed to the world around it becomes dry, and eventually becomes lethargic.

Sometimes, simply sitting back just watching. If you can offer security and an option of more luxurious homes You might be able to coax hermit back into its shell.

One of the most adorable aspects of hermit crabs may be how they treat their shells.

Have you ever noticed what happens when a hermit crab is prepared to swap shells? A group of crabs gathers to try on different shells according to their size until they have a perfect size–talk about teamwork!

What happens if you get home to discover one of the hermit crabs is out of the shell?

Are hermit crabs out of shell danger? Be careful, and let us assist you in figuring out the best way to help with your crab’s care.

Shells Are Important

If you’re the owner of a hermit crab, then you know the pleasure they have of hiding inside their shells. It seems that every time you move just way too fast, they pop back into their shells.

You know the importance of the sense of security that their shell gives.

Without this layer of protection, the exoskeleton can be exposed, making it vulnerable to external elements. Therefore, if you walk in to look at your crab only to discover they’ve broken out of their shell it is possible that you freak out for a few seconds.

Don’t make any assumptions at this point. We’ll explain why a hermit crab leaves their shell and how it is possible to aid the hermit crab’s return.

What Does a Shell Do?

The hermit crab’s shell creates a barrier of protection over its delicate exoskeleton.

Not only does it shield them from injury and injury, but it also stops their bodies from becoming dry. Without shells, this leaves your hermit crab vulnerable to air, heat, and light. They could quickly die without shells.

It is normal for crabs to leave their shell when they are molting. When they shed their exoskeleton and shed their shells, they re-shell themselves.

Symptoms of Shell Evacuation in Hermit Crabs

Unexpected stressors could cause your crab to quit its shell however, it may be molting.

If you observe your crab gorging its way through food, before suddenly stopping trying to scale the wall of glass in its home like it’s looking for an escape route, dragging its shell or large claw, or excessively hanging out in front of an empty water bowl or the makeshift pond, it could be showing per-molt behavior.

You might also observe your crab be lethargic. Perhaps the legs and body have been given the appearance of a light beige. The eyes of the animal may be facing outwards and its antennae might have stopped working.

If you observe any of these signs and your crab’s surroundings are perfect, you should wait for it to pass. The crab could soon shed its exoskeleton (molt). When it molts it’ll want to change into a larger shell Therefore, make certain to keep multiple sizes of shells empty in the area that is home to hermit crabs.

What is the Reason That Causes a Hermit Crab to Leave Their Shell?

Sometimes, the reason for evacuation is due to reasons different from molting or problems in the environment of your crab. Humidity levels in the environment may be too low or excessive (ideal humidity ranges from 70 to 80 percent) or the temperature could be too high.

Another cause that may trigger the crab to go out of its shell is the difficulty in accessing the food item. Are the sides of the food too high or is a crab playing with the crab and hindering the crab from eating?

In a tank that has multiple crabs, housing scuffles can ensue. Crabs could battle over shells that are desirable and have been reported to take one’s shell when the crab in need had been “trying out” an empty shell.

Therefore, a large shell selection, with a variety of sizes, should be offered, as the same style might not be suitable for the crab in question, but could be ideal for its tank partner.

There are times when the shell may cause irritation to your crab. Mites, sand, or other objects from outside can get stuck inside the shell which can cause the crab to flee.

The fungal infection or the bacterial one may also cause skin problems on the crab, and cause it to shed its shell. But, this issue is usually resolved with a molt.

Hermit crabs aren’t the most common species to be able to escape from their shell for a variety of reasons. They are mostly environmental however it could be a thing connected to their health. Let’s examine how this happens at all, and how you can prevent it from happening in the future.


However, stress may be caused due to the transportation and distribution of hermit crabs to pet stores. They can cause your crabs to be very unwell. If the crab you bought is stressed, it may cause it to break its shell and die.

It can be caused by physical damages, shipment issues, and poor treatment.

Shell Fighting

If you have several hermit crabs growing at various rates, and there aren’t enough shelves to hold the crabs, this could result in shell fighting.

This is when hermit crabs start fighting each other to get their shell Which can be very risky.

It could also happen that hermit crabs abandon their shell to search for a more suitable one, and then another takes the one they had previously used. Without a shell that fits your crab’s size, it’s in a bind till you get involved.


Hermit crabs can be exposed and may get debris and other irritants inside the shell. It is possible it is because the crab is trying to rid itself of the irritation by escaping the shell.

You must clean the inside of your body to ensure it’s clean of particles.

If the Environment is Unsuitable

Hermit crabs are very sensitive to their surroundings. This is also the reason to keep hermit crabs out of the shell. The crabs require a certain amount of moisture and a certain temperature in their cages to feel comfortable.

If it’s too cold or hot or cold, there are other factors taking over and making them uncomfortable. The possibility of them leaving their shell is to be expected in these situations.

Hermit crabs can be described as ectothermic meaning they require varying temperatures in their surroundings to regulate themselves. As with other cold-blooded species, They require a cool and warm part of the tank. They can freely move between the two according to what they require.

The top of the cage shouldn’t exceed 85 degrees F. The cold part of the cage must not fall below 70 degrees F. Both of these components must be readily available to them at all times.


In the end, your hermit crab will need to leave. After they die to the point of no return, they will fall out of their shell. It can be difficult to pinpoint the exact cause however, it could be due to age or undiagnosed disease.

How to Get Your Hermit Crab Back in Its Shell

Note that if your crab’s hermit is molting the molt stage, you can not read this section, instead go to another subheading.

Before you decide to place the hermit crab back into its shell it is important to be aware that this is a delicate procedure. Their bodies are extremely delicate therefore handling them may harm them or cause death. Therefore, it is essential to take care when handling them.

Before doing anything, take a few moments to gently scoop the hermit crab’s back legs, or scoop them up gently using an ice cube or other scoop.

Take a close look to ensure for any external injuries or signs of abnormality. If everything is just as it should be, then it’s time to tackle the shell.

Cook the shell inside de-chlorinated water to remove any bacteria or debris inside or around the shell.

Find a container that is big enough to hold the crab and shell. Add additional de-chlorinated water to the bottom to fill it up just enough to fill the bottom. This will allow the crab to retain the moisture required to be able to move back in easily.

Place the crab as well as the shell in a bowl that is sufficient to hold both of them. Keep an eye on it however, be careful not to disturb the crab. It could take a while before they re-shell.


If hermit crabs are taken out of their shell–whether due to a molt or some other environmental reason, it’s exhausted and vulnerable. Your crab requires protection from other crabs in the area and a bit of coaxing to ensure that it can get back into its shell.

Protect your crab’s home by transferring it to a hermit crab tank that is an isolation tank and quarantining it in a dome constructed from a large plastic soda bottle (cut in half in the middle, then open the top and close the hole).

The isolation area should contain approximately 6 inches of the substrate so that the crab can be buried and finish its molt. The molting process could take up to a month, so take your time. Make sure you have the ability to access food and water.

Make sure that your crab has plenty of different housing options, by offering the option of size shells. Some crabs are extremely specific about the design of the opening and design of the shell So, look for slightly larger shells in a similar design to that from their previous homes.

Before placing the shells in the habitat, clean them thoroughly and scrub off the debris, sterilize them for 15 to 20 minutes in boiling water. Then, let them dry and make sure there aren’t any foreign objects that have gotten in them. Once the shells have been cleaned and dry, spray them with a mix of sea salt de-chlorinated and then place these in the tank together with the crab you have isolated.

Keep an eye on your crab for several days to determine whether it’s warming up to an entirely new shell. It’s possible to take off one or two shells over the course of an hour or so and then return them to the environment until your crab is able to find a new home. Last but not least, leave your crab to its own devices and in darkness. The quiet and peace will eventually help you feel comfortable enough to allow it to experiment with a different shell.

Hermit Crabs Molting

It’s best if you do not handle the molting crab because they’re extremely fragile and delicate at this point. Instead, you can use the bottom dome part of the two-liter bottle to place it over the top of the crabs.

In the bottle allow for air circulation and then put two shells inside the container. them.

Keep in mind your crabby because they might attempt to dig deeper into the substrate. In the event of this happening, grab a scoop and begin digging into the substrate, allowing you to bring them up to the surface, without touching them.

Don’t add any more water. The body isn’t in the proper state to deal with the extra moisture.

When they are able to regain their strength, they’ll be able to climb back into the shell. Molting is a huge drain on energy and can leave your crab exhausted and vulnerable. Keep an eye on your crabs regularly to ensure they’re safe.

How to Prevent Shell Evacuation

You can avoid unwarranted shell evacuation by taking good care of your crab as well as its habitat. To start first, ensure that your enclosure for hermit crabs has the right humidity levels. Humidity is crucial to the health of your hermit crab as moisture aids them in breathing via their altered gills.

A hygrometer will allow you to ensure that your levels are correct. Also, spray your crab often (at least once per day) using warm distilled water to moisten its gills along the sides of the body.

The habitat for hermit crabs requires an adequate temperature. The ideal temperature range is 72 degrees to 80 degrees Fahrenheit. Ensuring this temperature allows the substrate of your tank to keep the same temperature gradient, which will keep the crabs comfortable.

To avoid fungal and bacterial infection, ensure that the environment of your crab has adequate airflow. Feed fresh food and eliminate any food items that are not consumed before it begins to mold and also keep its substrate, as well as water frequently to avoid the development of mold or algae.

Conclusion: Hermit Crabs Out Of Shell

The most important thing to remember from this is to not be panicked when hermit crabs are out of their shell. Keep calm and take action in the situation if needed. If you keep Hermit crabs then this is likely to happen at some time or another. Knowing how to re-shell the crab will enable you to help them without harming them or causing more harm.

While hermit crabs are out of shells, remember that when they’re molting do not handle them directly. Make a small space for them to take care of themselves when it’s time.


Dibyajyoti Bordoloi is the creator and author of, a third-generation experienced fish keeper and owner of a successful pet breeding farm. He is also a member of the Center for Wildlife Rehabilitation And Conservation (Assam), the Marine Aquarium Societies of North East India, and the Kaziranga Nature Conservancy of Assam.