Where Do Hermit Crab Shells Come From: Things You Probably Don’t Know Yet!

Hermit crabs obtain their shells from other animals as they do not produce their own shells. Hermit crabs use their hard shells to protect them while they reside in an ocean or tidal pool. Once the crab has molted, it will discard its old shell and replace it with a new one. Additionally, some hermit crabs may form collections of old shells from various animals they’ve eaten over time. All in all, hermit crab shells come from different sources.

Are Hermit Crabs Born With Shells?

No, hermit crabs do not naturally come with shells. Instead, they must steal them from other animals or form collections of old shells to protect themselves while they reside in an ocean or tidal pool.

Once molting has begun, the crab searches for a suitable place to cement its new shell and attaches it firmly to its body via claws and feet.

After settling on a location, the crab may live there for up to five years without ever taking off its shell again. Additionally, some hermit crabs may form temporary shells to evade predators or move to new hiding places.

Hermit Crabs: Getting The First Shell

It’s no secret that hermit crabs love a good shell-stealing spree; other hermits will often steal shells from other creatures, like clams and mussels. Once they reach the maximum size of 2 inches, they’ll need to find a new shell and start over again. Lastly, some hermit crabs may form temporary shells as needed.

The Sources of Hermit Crab Shells

Shells come in handy for hermit crabs when they need to protect themselves while living in an ocean or tidal pool. Hermit crabs can find shells from various sources, like other animals they’ve eaten, rocks, and even old gloves. Hermit crabs use empty mollusk shells as homes when not in their shells.

How Do Hermit Crabs Get New Shells?

Once a hermit crab has reached the maximum size of 2 inches, it’ll need to find a new shell. Some may steal shells from other creatures, while others may form temporary shells. All in all, it’s a pretty ingenious system that hermit crabs have come up with to get by in life.

Scavenging for Empty Shells

If no suitable shells are available, hermit crabs will often scavenge for empty ones. Instead, they’ll search through rocks and other debris in tidal pools or the ocean floor for any old shells that may still have some meat or soft tissue inside them. Additionally, they’ll sometimes use old gloves or other objects as shells.

Dead Hermit Crabs

Some hermit crabs may even use the empty shells of dead hermit crabs as their homes. These creatures are typically very resourceful and will reuse any old shell that comes their way, no matter how small or large it may be. Additionally, they’ll clean the inside of the old shell and add fresh sand to it if needed.

Fighting Other Hermit Crabs

If there aren’t any shells to be had, hermit crabs may fight for the right to live in an old shell. Instead, they’ll use their claws and teeth to bulldoze their opponents out of the way and take possession of the desirable territory.

This means that fighting for territory is integral to hermit crab life.

The fight’s winner usually ends up with a vast and robust shell, making them the dominant crab in their community. This makes it crucial for them to stay on top of things lest they be ousted from their home by another crab with a better strategy or more robust claws.

How Often Do Hermit Crabs Change Shell?

There is no definitive answer to this question. Sometimes hermit crabs will switch shells multiple times per day, while other times, they may only do so once or twice over a week or month. It all depends on the availability of empty shells and how active the hermit crab population is at that particular moment.


After molting, hermit crabs will often change shells again because their old shell is no longer waterproof and can’t protect them from the elements or predators. Instead, by switching to a new shell, the crab can start anew and build his strength for the successive molt.

After Conflict

After the conflict, hermit crabs use their old shells as shelter. This is a clever way of avoiding being attacked or having conflicts in the first place. The new shell is grown over about three weeks, and sometimes hermit crabs can be seen with more than one shell – this signifies that they haven’t found the right one yet!

General Changing

Hermit crabs also change shells for a variety of other reasons, such as when they’re growing or molting. This is why it’s essential to watch your crab see what type of shell he is using – if it’s not his usual one, there might be a reason for that.

Hermit Crabs’ Guide to Choosing Shells

Hermit crabs don’t have a specific preference for shell shape or size. Instead, they mainly choose them based on their availability and current lifestyle needs. So, if you see your crab switch shells often, it’s not necessarily a sign that he is unhappy – it could simply be due to his changing needs.


Another factor that hermit crabs consider when choosing a new shell is the smell. Some shells are better at repelling predators or attracting prey, so they must find the right one for their needs. The smells of different shells will also help hermit crabs decide if they should inhabit them or not.


Hermit crabs also look for shell sizes that match their body size. If they plan to stay in the same shell for a while, they will usually choose a larger one. However, if they expect to molt soon and need a new smaller one, they will use an existing small shell as shelter until the bigger one arrives.

When a hermit crab reaches maturity, it ceases to make new shells and instead relies on its old ones – this is why giant hermit crabs often have lots of old shells around!


When choosing a crab shell, durability is of utmost importance. The shell must be strong enough to protect the crab from predators and store food and water. Additionally, it should fit your specific needs – size, shape, color, etcetera. Finally, the hermit crab selects the most durable shell for its lifestyle and environment.


Another factor to consider when choosing a shell is mobility. If the crab needs to move around frequently to find food or new shells, it will choose a shell that is easy for him to get out of and into. Additionally, a mobile shell will be less likely to become snail-bound.