Why Isopods Eat Their Molts

After molting, many isopods eat their shed exoskeleton. This behaviour allows them to recycle calcium and other nutrients needed to strengthen their new shell.


By Lee Brookes
2 min read


Why Isopods Eat Their Molts

Isopods often eat their shed exoskeleton after molting. While this behaviour may look unusual, it plays an important role in their survival and growth.

The old shell contains valuable nutrients, especially calcium, which can be reused to strengthen the new exoskeleton.

What Happens During Molting

Isopods grow by shedding their exoskeleton in a process known as molting. Unlike many arthropods, isopods molt in two stages. They first shed the rear half of their shell and later shed the front half.

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

Why Isopods Eat the Old Exoskeleton

The shed exoskeleton contains minerals that the isopod invested energy to produce. By eating the old shell, the isopod recovers these nutrients rather than losing them.

Calcium is particularly important because it helps harden the new exoskeleton after molting.

The Importance of Calcium

Calcium is essential for isopods because it strengthens their protective shell. Without adequate calcium, molting can become difficult and the new exoskeleton may remain soft.

Providing additional calcium sources within the enclosure helps support healthy molting.

Our guide on best calcium sources for isopods explains several options for maintaining calcium levels.

When Isopods Eat Their Molts

Most isopods consume the shed exoskeleton shortly after molting. Because the new shell is soft, the isopod often remains hidden while eating the old molt.

This behaviour helps them recover nutrients while staying protected during a vulnerable stage of development.

Supporting Healthy Molting

Healthy molting requires proper enclosure conditions. Stable humidity, adequate calcium, and access to natural foods all help support this process.

Providing leaf litter and decomposing wood allows colonies to access natural nutrients. Maintaining a layer of leaf litter also supports the enclosure ecosystem.

Final Thoughts

Eating their molts allows isopods to recycle valuable nutrients, especially calcium. This behaviour is a natural part of their growth cycle and helps strengthen the new exoskeleton after molting.

When colonies have access to calcium sources and stable enclosure conditions, molting usually occurs without problems.

Learn More About Isopod Biology


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