Skip to Content

Why Does My Hermit Crab Keep Switching Shells?

Why Does My Hermit Crab Keep Switching Shells?

Share this post:

The purpose of this blog is to share general information and is written to the author's best knowledge. It is not intended to be used in place of veterinary advice. For health concerns, please seek proper veterinary care. In addition, as an Amazon Associate I earn from qualifying purchases.

Hermit crabs are such fascinating creatures. Many people have started to keep them as pets in their homes.

They’re exotic pets, but they can be a lot of fun to take care of. If you have two or more hermit crabs in your habitat, you might notice that they are behaving strangely.

If the hermit crabs keep switching shells, you might be wondering what that means. When hermit crabs switch shells with each other does it mean something specific?

What about when one hermit crab just keeps switching shells in the tank? If the hermit crab doesn’t seem satisfied with any of the shells, is that a sign that something is wrong?

Read on to learn about hermit crabs switching shells. You’ll know what is really going on when you see hermit crabs doing this.

The Hermit Crab Can’t Find a Shell That’s the Right Size

The most likely thing that’s going on is that the hermit crab is having a hard time finding the right shell. Hermit crabs need to find shells that are the right size for their bodies.

If your crab keeps changing shells repeatedly, it might be that none of the shells are appropriate. Perhaps the hermit crab feels that it needs a shell that is better for its size.

When keeping a pet hermit crab in your home, it’s best to put various shells of different sizes in the tank. This will ensure that the hermit crab has options

Go out and buy some shells that the hermit crabs can use. Ideally, you should buy two of each shell size so you can avoid issues between the hermit crabs.

Finding shells won’t be a problem since you can get what you need at local pet stores. It’s also possible to order shells online and have them shipped to you.


Could it be that your crab is stressed about something in the tank? Sometimes stressed hermit crabs will exhibit unusual behavior.

If your hermit crab isn’t being cared for properly, it might start switching shells constantly or doing other strange things. It’s likely worthwhile to check the environment to see if there are any issues.

For instance, there could be something wrong with the humidity levels in the habitat. Remember that hermit crabs need to have high humidity in the tank to be able to breathe properly.

You’ll also want to make sure that you’re feeding the hermit crab properly. Hermit crabs that are being fed a healthy diet will be less likely to become stressed.

Do your best to fix any issues that might be causing stress. It could make it so the hermit crab will start acting normal again.

Hermit Crabs Will Fight Over Shells

You know that it’s recommended to keep at least two hermit crabs in a home habitat. They’re social creatures that do better in groups than they do alone.

That doesn’t mean that hermit crabs won’t fight sometimes. If two hermit crabs want the same shell, they might wind up fighting for it.

The hermit crab that wins the fight gets to take the shell. Two hermit crabs can hurt each other by fighting over shells like this.

If you’re noticing a lot of shell switching or drama in the hermit crab habitat, it could be that there’s only one shell that is the right size in the tank. Perhaps you need to buy more shells so that the hermit crabs won’t have to fight.

Buying at least two shells of each size makes it easy to avoid such problems. You should have many shells in the tank that the hermit crabs can utilize.

Buying hermit crab shells won’t cost too much money overall. You can get what you need and the hermit crabs won’t have to fight each other to find a shell that’s the right size.

It Might Not Be Anything to Worry About

It’s also possible that it might not be anything to worry about. There are many shells in the crab’s habitat, and it might just feel like trying out different ones.

So long as you’ve done the work to keep the crab’s habitat in good shape, you won’t need to be worried about the crab becoming stressed. Hermit crabs that are living in good habitats are likely going to be just fine.

If there are many shells in the tank of various sizes, your hermit crab should settle on one eventually. You might notice it trying out shells for quite some time until it finally gets the perfect one.

Sometimes hermit crabs aren’t smart enough to realize when they’re going back and forth between the same two shells. It might take the hermit crab a while to finally discover the shells in the habitat that are of the appropriate size.

Just monitor the hermit crabs and make sure that they’re doing well. There aren’t any predators in the tank to worry about so your hermit crabs will be fine even if they’re switching shells a bit more than usual.

How Often Do Hermit Crabs Normally Change Shells?

Usually, hermit crabs will change shells when they outgrow their current shells. This generally means that they’ll change shells when they decide to molt.

Juvenile hermit crabs molt more often than adult hermit crabs. A young hermit crab might molt every six months.

Older adult hermit crabs might only molt every 18 months. So the amount of time it will take the hermit crab to want to change shells will depend on how old it is.

A hermit crab might change shells a few times per year when it’s young. It’s also normal for hermit crabs to move to smaller shells for a bit because they shrink during the molting process.

Then they grow and move up to the larger shell after the molting is over. It’s an interesting process.

How Long Should It Take a Hermit Crab to Change Shells?

There isn’t a specific amount of time that it should take a hermit crab to change shells. It might happen fast, but it could take up to a week.

Keep in mind that these shells are like the hermit crab’s home. It might take a crab a while to get comfortable with a new shell. Give it a bit of time and it should make a decision before too long.

As mentioned earlier, sometimes hermit crabs go back and forth between the same two shells. They aren’t always smart enough to realize that they need to try different shells.

Some owners have found success by rearranging the shells in the tank to get the hermit crabs to notice them. This could be a good option if you feel that your hermit crab is struggling to find the right shell.

Hermit Crabs Will Sometimes Exchange Shells

It’s not unusual to see a group of hermit crabs exchange shells. In the wild, people have observed hermit crabs lining up by size to exchange shells.

They will swap shells based on size so that each crab can find an appropriate home. This is an interesting thing that you might observe happening if you have a group of hermit crabs in your home habitat.

It’s very intriguing that hermit crabs are capable of doing things like this. They aren’t always smart enough to realize when they’re going back and forth between the same shells, but they’re wise enough to know to exchange shells for the sake of convenience.

If you ever see hermit crabs doing this, it’s a normal thing that you don’t need to worry about. It’s something that you might very well find to be entertaining to watch.

How Long Do Hermit Crabs Live?

Hermit crabs can actually live for quite a long time. They’re not that hard to care for, and even novices can get hermit crabs to live for many years in captivity.

The average life span of a captive hermit crab is much longer than that of a wild hermit crab. In captivity, hermit crabs don’t have to worry about predators and other dangerous things.

A pet hermit crab should live between 5 and 15 years on average. Since they can survive for so many years, they’re going to be good pets for those who want to enjoy their pets for a long time.

Some hermit crab enthusiasts have done such a good job of caring for hermit crabs that they’ve lived for 30 years. That might not happen in your situation, but it’s interesting to know that it’s a possibility.

Final Thoughts

If you see your hermit crabs constantly switching shells, it’s likely that they’re just trying to find the right size. Hermit crabs grow and they need to change shells every so often.

It could be that the hermit crabs don’t have shells that are the right size in the tank. You may need to go out and purchase more hermit crab shells to put in the tank.

Buying multiple shells of the same size is a good idea, too. You don’t want your hermit crabs to fight over one shell.

Sometimes hermit crabs will act strange when they’re stressed as well. It might be wise to check the environment to ensure that nothing is amiss.

If you keep all of this in mind, it’ll be easy to help your hermit crab. Enjoy your pet hermit crabs and they’ll thrive in your tank for a long time.

Share this post: