Hermit crabs are some of the most interesting creatures on the planet. Many people think that they’re so fun to watch.
These creatures are famous for hiding in their shells. Currently, many people like to keep hermit pets as pets.
You might not know a lot about hermit crabs. If you’d like to learn about hermit crabs and their shells, keep reading.
Below, you’ll find information about hermit crab shells and where they come from. You’ll know a lot more about these crabs once you’ve read everything.
Are Hermit Crabs Born With Shells?
No, hermit crabs are certainly not born with shells. Some might think that hermit crabs would be born with shells due to how much they rely on them.
This simply isn’t the case. Hermit crabs begin their lives without shells and they then look for shells that have been left behind by dead creatures.
Shells are an imperative part of a hermit crab’s life. Without a shell, a hermit crab would be very vulnerable indeed.
Hermit crabs have relatively soft bodies that wouldn’t be able to survive attacks from predators. So using shells can be seen as a way to make up for an inherent weakness.
How Long Can Hermit Crabs Live Without a Shell?
It’s unlikely that a hermit crab will live for very long without a shell. A shell provides protection to the hermit crab in various ways.
Without a shell, a hermit crab would be very vulnerable to predator attacks. Even if the crab doesn’t have to worry about predators, it’s still in a bad position without a shell to call its own.
Hermit crabs will be extremely vulnerable to heat and light without a shell. Also, hermit crabs typically store water in their shell, and this water is used to help them keep their gills moist.
Living without a shell is simply not normal for a hermit crab. There’s a good chance that the hermit crab would die quickly without a shell.
When a hermit crab is without a shell, it’ll comb the area to try to find a shell. It’s not normal for a hermit crab to remain without a shell for long.
Can Hermit Crabs Live Without a Shell?
No, hermit crabs can’t live without a shell for very long. A hermit crab won’t instantly die if it leaves its shell, but it’ll do its best to seek out a new shell as soon as it can.
Hermit crabs rely on shells for protection so much that they basically can’t function without them. They have learned to live by using shells to make up for weaknesses that they have.
For a hermit crab, a shell is pretty much everything. So it’s not good for a hermit crab to be without a shell even for short periods of time.
Hermit crabs typically only leave their shells briefly. They will leave a shell to relocate to a new shell when necessary, but there are few other situations that will cause them to leave their shells.
Where Do Hermit Crabs Get Their Shells?
Hermit crabs get their shells by finding them somewhere on the beach. They take shells that have been left behind by dead mollusks.
Typically, the shells that are used by hermit crabs used to belong to sea snails. They wind up taking the shells as their own and using them to protect themselves.
Hermit crabs choose shells based on many different factors. Some hermit crabs choose shells based on a preference for the type of opening they have.
Of course, the size of the shell needs to be appropriate for the hermit crab as well. It’s interesting to see these creatures looking for shells and ultimately choosing a shell.
Why Do Hermit Crabs Change Shells?
Hermit crabs change shells because they outgrow their shells over time. Like most creatures, hermit crabs are going to keep growing as they age.
A hermit crab grows and it’ll eventually need to find a larger shell to accommodate its larger body. When a hermit crab gets an opportunity to move into a larger shell, it’ll do so when necessary.
Hermit crabs will actually line up to exchange shells with each other sometimes. Each crab will wind up moving into appropriately-sized shells.
So hermit crabs are going to need to change shells from time to time. They can’t just keep living in the same shell because it’d be far too small for them once they grow.
How Often Do Hermit Crabs Change Shells?
You’ll find that hermit crabs change shells after molting. Molting occurs when hermit crabs are growing and they need to grow a new exoskeleton.
Hermit crabs have exoskeletons that don’t grow with them. They shed their old exoskeletons and grow new ones during the molting process.
It’s normal for hermit crabs to molt once every twelve to eighteen months. So that will be about how often a hermit crab will need to change shells.
Of course, this information can differ depending on various factors. Sometimes hermit crabs might molt a bit more often when they need to recover from injuries such as losing a leg.
The real answer is that hermit crabs will change shells as often as they need to. You should also have replacement shells in the tank for your pet hermit crabs.
When Do Hermit Crabs Change Shells?
As mentioned above, hermit crabs change shells when they start to grow larger. They won’t change shells unless they really need to, in most circumstances.
So when a hermit crab grows it’s going to have to change to a new and larger shell. There are times when hermit crabs might not be able to change shells right away due to not being able to find a larger one.
In the wild, hermit crabs might have to wait for a new shell to appear. Pet hermit crabs should be given many different shell options.
You can keep various shells that are different sizes in the tank. This should make it easy for your pet to find a shell that is the perfect size.
It might be wise to buy several shells that are larger than your hermit crab’s current shells. Try to give your hermit crab a few options so it can find the shell that it feels is the best fit.
Do Hermit Crabs Poop in Their Shell?
Yes, hermit crabs typically poop in their shells. This likely seems rather gross, and it sort of is when you think about it.
The hermit crabs don’t keep the poop in the shells. They have anuses at the base of their bodies like many other animals do.
A hermit crab anus is actually referred to as the telson. The poop comes out of the telson and winds up touching the shell.
Once a hermit crab has defecated, it’ll use its back legs to fling the poop out of the shell. So the poop will wind up being located somewhere on the sand or elsewhere in the habitat.
Can Hermit Crabs Get Stuck in Their Shell?
Sadly, it is possible for hermit crabs to get stuck in their shells. This usually only occurs when people try to put hermit crabs in painted shells, though.
You’re never supposed to use painted shells for hermit crabs. This is a bad practice that some pet stores might utilize to try to make the hermit crabs look more appealing.
Don’t automatically assume that your hermit crab is stuck in a shell, though. Remember that they like to hide in their shells and don’t always come out.
If you’re sure that the crab is stuck in its shell, it’s best to reach out to an exotic veterinarian. They can consider the best course of action to help the crab without harming it.
Generally, you should never try to forcefully remove a hermit crab from its shell. It’s likely that you’ll seriously injure the crab, and you might even kill it.
Why Does the Hermit Crab Live in a Shell?
Hermit crabs live in shells because they need the protection of the shell. These creatures have learned to use shells left behind by mollusks to better live their lives.
It’s interesting to see how good hermit crabs are at using their shells. They can move around very well while inside the shell.
Hermit crabs hold onto the shell with two of their legs while the other legs are used for walking. They can fully retreat inside the shell when necessary, too.
These shells allow hermit crabs to protect themselves from predators. They also help to block light and lessen issues with excessive heat.
Hermit crabs store water in their shells so they can keep their gills moist. Land hermit crabs have modified gills that can breathe oxygen, but they must stay moist to be able to do so.
Without a shell, hermit crabs wouldn’t be able to function properly. As noted earlier, hermit crabs won’t live long without a shell.
How to Make Hermit Crabs Come Out of Shell
There are a few ways that you can make hermit crabs come out of their shells. However, it should be noted that you don’t need to do this.
Generally, there isn’t a good reason to coax a hermit crab to come out of its shell. The hermit crab will come out of its shell when it needs to.
The most practical way to get a hermit crab to poke its head out of its shell is to offer it food. This should make the hermit crab come out a bit just so that it can eat.
Another way to do this is to handle the hermit crab. Hermit crabs will generally come out of their shells when they’re being handled.
However, handling is stressful for hermit crabs. So you should keep handling to a minimum.
Sometimes hermit crabs might pinch their owners when they’re being handled. You need to be careful when handling hermit crabs or they can come to harm.
Submerging a hermit crab in water will make it come out of its shell, too. Some people give hermit crabs baths periodically, but you don’t really need to do this under normal circumstances.
Turning up the heat can get hermit crabs to come out of their shells. This can be sort of dangerous, though.
Hermit crabs shouldn’t be allowed to get too hot. You don’t want the hermit crab to dry out since it might have trouble breathing.
What Are Hermit Crab Shells Made Of?
The shells that hermit crabs use are originally made by sea snails. These shells are made when the snails secrete calcium carbonate.
So the shell is made of calcium carbonate. Over time, the calcium carbonate becomes a hard shell.
These shells are held together by thin organic membranes. They do a good job of protecting both sea snails and the hermit crabs that use the shells once the sea snails have passed away.
Why Would a Hermit Crab Keep Switching Shells?
There are times when hermit crabs will switch shells repeatedly. This often occurs when a hermit crab is having trouble finding the right shell size.
You might not have a shell that is the right fit for the hermit crab in the tank right now. It could be that you simply need to buy more shells of different sizes to give the hermit crab better choices.
Sometimes hermit crabs will get confused as well. For example, a hermit crab might fall into a pattern of going back and forth between the same two shells.
Hermit crabs seem pretty smart sometimes, but they’re still simple creatures that lack complex brains. A hermit crab might not always be able to realize that it’s already tried out a specific shell to see if it’s a good fit.
This means that rearranging the shells might help the hermit crab to find its new home. Give this a shot if your hermit crab seems indecisive and you’re sure that you have a shell that’s a good fit for it in the tank.
Where Do You Buy Hermit Crab Shells?
Hermit crab shells can be purchased from many different places. Pet stores that sell hermit crabs will often have shells that they sell.
You can go look at local pet stores and pet supply stores to see what you can find. Remember that you only want natural shells.
Never buy painted shells since those are very bad for hermit crabs. If you have trouble finding what you need locally, you can always buy hermit crab shells online.
Popular online marketplaces and large pet store chains will sell what you need. You can have the shells shipped to your home directly.
Keep Multiple Shells of Each Size in the Tank
It’s always best to keep multiple shells of each size in the hermit crab tank. Why does this matter, though?
Hermit crabs are social creatures and it’s said that you should keep them in small groups. Keeping one hermit crab by itself is something that many people say is cruel.
This means that most people will keep at least two hermit crabs together. Sometimes hermit crabs will fight over shells if they both need a shell that’s the same size.
You can avoid such issues by keeping multiple shells of each size in the tank. It’s a good way to keep your hermit crabs safe.
Hermit crabs can injure each other when they fight. Sometimes hermit crabs will even lose legs or claws when they fight each other.
Problems like this can be very stressful to deal with. While hermit crab claws and legs can grow back, it’s not something you want to see happen.
Keep the peace in the tank by ensuring that there are more than enough shells. You don’t want your hermit crabs to feel as if they need to compete for shells.
You’ve learned so much about hermit crabs and hermit crab shells now. Shells are so important to hermit crabs.
These creatures truly cannot get by without shells. They don’t grow their own shells, though.
Hermit crabs find shells that have been left behind by dead sea snails. They live in the shells and use them to protect themselves.
Every so often, hermit crabs will need to change shells. They do this when they grow.
A growing crab will need to find a larger shell that can accommodate its larger body. This should occur every twelve to eighteen months on average.
When caring for pet hermit crabs, it’s important to keep replacement shells in the tank. You should have many shells for the hermit crab to choose from.
You also want to keep multiple shells of each size in the habitat. This is to prevent fighting between hermit crabs.
Now you should feel more confident that you understand hermit crabs and their shell needs. Use this information to help care for pet hermit crabs and keep them healthy.
Jeff has always enjoyed having pets, but as a child, he was drawn to his family’s fish tank. Being able to maintain a small ecosystem and observe the behaviors and interactions in the underwater world peaked his interest early on and has kept him hooked until this day. On Avid Aquarist, Jeff shares everything he’s learned about helping aquatic life survive and thrive in a home aquarium.