Are Hermit Crabs Born With Shells: Interesting Ways They Get Shells

Typically, hermit crabs are not born with shells; instead, they must scavenge one or find a discarded shell to reside in while they grow and develop. In addition, some hermit crabs may “adopt” a new shell if they find one that fits them well. Lastly, some hermit crabs may make a temporary shell from materials they find around them.

Getting Their First Shell

Hermit crabs find shells by scavenging or adopting them. They may search for an old one discarded or scavenge one from the environment. If they do not find a suitable shell, they may make something temporary out of materials found around them.

The shells of hermit crabs can be found on beaches, in the sand, or other places near the water. Hermit crabs may scavenge for pieces of broken shells or excavate new ones from the sand. Once a crab finds a suitable shell, it will replace any missing parts with mucous secretions and bits of coral reef material.

How Hermit Crabs Get New Shells

Hermit crabs may find new shells by scavenging, adopting, or making a temporary one. To survive, Hermit crabs must replace their shells every four to eight weeks. They find new shells by raiding other crab’s homes or scavenging on the beach/ocean.

It can take up to 6 months to fully adjust to life inside their new shell! Once they find a suitable Shell, they burrow into it and cement it shut with mucous secretions from their body. Additionally, the spines on the top of their feet help them hold onto their new shell.

Scavenging for Empty Shells

Hermit crabs may scavenge for empty shells on beaches and in the sand. They remove the pieces of coral, oysters, and other small animals from the shell with their claws. Additionally, they may chew small holes in the shell to get inside. When they find an empty shell, they will remove all the pieces and soil from it.

Dead Hermit Crabs

Occasionally, a hermit crab will find a dead or abandoned shell. If the crab can access the hinge and lock tabs on the shell, it will use its claws to get inside. Once inside, it can chew small holes in the shell so it can move around comfortably. Hermit crabs may use dead shells as their new home for up to six months or longer!

Fighting Other Hermit Crabs

Hermit crabs may fight for shells if they cannot find any. They will use their claws, antennae, and spines to damage or remove the shell from another crab.

Also, hermit crabs may expel a foul-smelling liquid from their bodies when fighting. This liquid can irritate other animals and cause them to avoid the area. Additionally, hermit crabs may try to steal each other’s food.

How Often Do Hermit Crabs Change Shell?

Molting, or the process of changing shells, is a traumatic event for crabs, and it’s essential to provide them with a safe place to do it. Most hermit crabs change their shell only once during their lifetime – a critical process known as molting. Additionally, some hermit crabs may change their shell more than once.


Hermit crabs usually molt (change their shells) about every six months. As they do so, the old shell is left behind – known as the ‘cast exoskeleton.’ Newly molted crabs look different from the older ones as they have a whiter shells.

After molting, hermit crabs may feel a sense of insecurity. They may avoid light and move around frequently in their new shell to ensure it’s strong enough. Additionally, they may expel a foul-smelling liquid from their body to mark the territory as their own. Once they’re comfortable in their new shell, hermit crabs will resume eating and drinking and start reproducing!

After Conflict

If there’s a conflict between hermit crabs over a shell, the older crab will usually try to ‘dominance’ the younger one, for example, by eating more or fighting more frequently.

This can be stressful for the younger crab and may make it less likely to find a new shell later in life. Additionally, when hermit crabs conflict, they will often change shells, providing an alternate refuge from the situation.

General Changing

Although molting is a significant and traumatic event for hermit crabs, it’s not the only time they’ll change shells. Hermit crabs will also change their shells when they’re born, grow larger or smaller (in response to food availability), and when reach sexual maturity.

How Do Hermit Crabs Choose Their Shells?

Hermit crabs can change their shells anytime, but they typically choose to do so when they reach sexual maturity. Hermit crabs are looking for a solid and protective shell at this stage. Factors determining which type of shell to form include the size and shape of the crab’s head, body, claws, legs, and antennae.


One factor that hermit crabs consider when choosing their new shell is the smell. If they live in an area with many other creatures, they may prefer a scentless shell so as not to be identified and targeted. Also, hermit crabs often choose a more giant or protective shell if they live in an area with strong smells (like ocean water).


Another factor that hermit crabs consider when choosing their new shell is the size. Hermit crabs often choose a smaller, weaker shell if they live in an area with more giant creatures.

However, suppose they live in an environment with very little competition (like on a coral reef). In that case, they may prefer a more extensive and more robust shell to have more excellent protection from predators. Also, hermit crabs living in warm climates may choose a smaller, lighter shell to help them keep cool.


Another factor that hermit crabs considered when choosing their new shell was durability. Hermit crabs will often choose a more robust, durable shell if they live in an environment with a lot of physical activity (like on the ocean floor).


Mobility is an essential aspect that hermit crabs need to find new shells if theirs get damaged or destroyed. Factors like size, shape, and location play a role in the crab’s mobility. For example, giant hermit crabs are more mobile than smaller ones as they can travel long distances to search for a new shell.

Hermit crabs can also move their legs sideways, enabling them to easily slip through small gaps between sand grains (a characteristic that helps them escape predators). When a hermit crab no longer has empty shells left, it will eventually die due to lack of mobility.

Additionally, some hermit crabs choose to live permanently inside of a single shell. This helps them conserve energy and protect themselves from the elements.

Should I Change My Hermit Crab’s Shells?

There is no definite answer as to whether or not hermit crabs should change their shells. Factors like mobility, size, and shape will all play a role in the decision-making process. Ultimately, it is up to the individual crab to decide what type of shell fits best for them.

Remember to be patient – hermit crabs are naturally curious and might take a little longer than expected to finish their new shell. If you notice any signs of wear and tear, or your crab is growing too big for its current shell, it’s time to get them a new one!

Finally, keep your hermit crab clean and free of parasites – this will help them stay healthy and happy.

Helping Hermit Crabs Find New Shells

If your hermit crab needs new shells, you can do a few things to help. First, ensure the area where your crab is searching for a new home is clean and clear of any obstructions. This includes rocks, sticks, and other debris.

Secondly, create tiny openings in the objects nearby your crab’s natural habitat so that they have easier access to find a new shell. For example: if you live near an ocean beach with large waves crashing onto the shoreline daily, drill tiny holes into some of the larger pieces of driftwood.

Finally, ensure your crab has plenty of hiding places inside and outside its new shell. This will help him, or her feel safe and secure while searching for a permanent home.

Encouraging Hermit Crabs to Change Shells

It will take some time for your hermit crab to grow a new shell, but you can help by being patient. However, if your crab refuses to change shells, some factors may prevent it. In this case, you might need to provide a new one or help the hermit crab remove its old one.

However, if molting doesn’t seem to be working – the most common reason why crabs don’t molt might be because the old shell does not fit well and is uncomfortable. So you can encourage your hermit crab by providing plenty of hiding places and food.

It’s also helpful to provide a small opening for the crab to crawl through to have easier access to the new shell. For example, you can use PVC pipe, threaded metal wire, plastic wrap tubes – whatever is available around your home. Be sure to check on your crab regularly and make sure that everything is still going smoothly.