What Happens When Isopods Molt

Molting allows isopods to grow by shedding their old exoskeleton and forming a new one. This process is essential for development and happens many times throughout an isopod’s life.


By Lee Brookes
2 min read


What Happens When Isopods Molt

Isopods grow by shedding their outer shell, a process known as molting. Because their bodies are protected by a rigid exoskeleton, they must periodically replace it in order to increase in size.

Molting occurs throughout an isopod’s life and is particularly common during early growth stages.

Why Isopods Need to Molt

An isopod’s exoskeleton does not expand as the animal grows. Instead, the isopod must shed the old shell and form a new one that allows for additional growth.

This process allows the isopod to gradually increase in size over time.

Our guide on how fast baby isopods grow explains how molting supports early development.

The Two-Part Molting Process

Unlike many other arthropods, isopods molt in two separate stages. They first shed the back half of their exoskeleton and later shed the front half.

During this period, the isopod may appear to have two different colours on its body as the new shell begins to form.

You can learn more about this unique process in our article on why isopods molt in two parts .

What the New Exoskeleton Is Like

After molting, the new exoskeleton is soft and flexible. Over time it hardens as minerals such as calcium are absorbed.

Because of this, calcium sources are very important for healthy molting.

Our guide on best calcium sources for isopods explains how to provide calcium in an enclosure.

Why Isopods Eat Their Old Shell

Many isopods will consume their shed exoskeleton after molting. This behaviour helps them recover nutrients, especially calcium, which can be reused to strengthen the new shell.

This behaviour is explained in our article on why isopods eat their molts .

Signs an Isopod Is Molting

Isopods preparing to molt may show several behaviours.

  • Hiding under moss or leaf litter
  • Reduced movement
  • Visible colour difference between body segments

Providing stable humidity and calcium-rich foods helps ensure successful molting.

Supporting Healthy Molting

Proper enclosure conditions make molting easier for isopods. Deep substrate, leaf litter, and decomposing wood provide both shelter and nutrients during this vulnerable period.

Our guide on why rot wood is important for isopods explains how decaying wood supports colony ecosystems.

Final Thoughts

Molting is a natural and essential process that allows isopods to grow and maintain healthy exoskeletons. By providing calcium sources, stable humidity, and a natural enclosure environment, keepers can support successful molting throughout the colony.

Learn More About Isopod Biology


Leave a comment

Please note, comments need to be approved before they are published.