Hermit Crab Articles

An Introduction to Hermit Crabs

Building a Great Crabitat

Choosing a Substrate for my Land Hermit Crabs

Creating a Great Home for your Hermit Crab

Feeding your Land Hermit Crab

Food and Water for Your Hermit Crab

Hermit Crab Cages

Hermit Crab Food

Hermit Crab Mating - Does Hermit Crab Breeding Occur in Captivity?

Hermit Crab Molting

Hermit Crab Molting - Understanding the Molting Process

Hermit Crab Shells

How many species of land hermit crabs are kept as pets?

Interesting Hermit Crab Facts

Land Hermit Crab Molting

Recommended Diet for a Pet Land Hermit Crab

Selecting your Land Hermit Crab

The Basics of Hermit Crab Behavior

The Daily Care of Hermit Crabs

The Importance of Hermit Crab Shells

The Importance of Temperature for Hermit Crabs

The Ugly Truth About Pretty Shells

Tips for Handling Your Hermit Crab

Water is the Most Important Hermit Crab Need

What Kind of Water Should My Hermit Crab Drink?



The body skeleton of a hermit crab is much different from that of mammals, reptiles, birds and fish. Their skeleton is on the exterior. It is called the exoskeleton. The exoskeleton is made of a material called chitin. It protects the crabs' organs from damage. The exoskeleton holds 90% of a hermit crabs calcium.


In order for a hermit crab to grow it must go through a process called molting. Just before molting, hermit crabs will drink a lot of water. This will increase their body weight by 25%. Sacs called Pericardial sacs fill with a mucus like substance that swells and splits the exoskeleton. The extra water is used by the hermit crabs circulatory system to increase the their body size (legs & claws) enabling them to regenerate any missing appendages.


Hermit crabs need two things to successfully molt and increase their size, water and calcium. Calcium is present in the shells and sand they eat. Since they lose 90% of their calcium when they shed their exoskeleton, they will eat their exoskeleton to regain it. Just before a female hermit crab molts her egg sac will swell. If she hasn’t successfully mated she will shed the egg sac along with her exoskeleton.

When your hermit crab does molt, it is important to leave them alone and keep the environment quiet. This is one of the benefits of having a hermit crab living separated. If your hermit crabs all live in one aquarium and you are not familiar with the signs of a hermit crab that is about to molt, your hermit crab can be in a lot of danger because of its vulnerable state.


Hermit Crab Molting Signs: