Millipedes moult by shedding their old exoskeleton and growing a new one underneath. They usually bury themselves first, then stay hidden while the new body hardens, so a buried millipede should generally be left alone.

What happens when a millipede moults?

Like other arthropods, millipedes have a hard outer covering rather than an internal skeleton. Because that covering cannot grow continuously, it has to be split and shed at intervals. This process is called moulting, or ecdysis.

Before moulting, a millipede usually becomes less active and retreats into the substrate. Many species bury themselves deeply in a quiet, humid part of the enclosure. When the old shell is shed, the new body is soft, pale and flexible for a time, then gradually hardens and darkens.

In many cases you will not see the moult itself. You may only notice that the millipede has disappeared below the surface and later reappears looking lighter in colour.

Why the topic matters

Understanding moulting helps keepers avoid mistaking a buried millipede for one that is inactive, stressed or dead. A period underground is often normal, especially if the enclosure conditions are suitable and the animal is otherwise healthy.

It also shows why enclosure design matters. Millipedes need deep substrate that supports burrowing and stays moist without becoming waterlogged. If the setup is shallow or dry, the animal may not have the right conditions to moult safely.

If you want a broader overview of the life stages involved, the Millipede Breeding, Moulting & Lifecycle Guide is a useful place to start, and our Millipede Breeding & Lifecycle Guides hub brings the related articles together.

Useful context for keepers

When a millipede buries itself, the first things to check are the enclosure conditions: substrate depth, moisture and overall stability. A healthy setup should let the animal stay underground undisturbed, with enough organic material to match how it lives in nature.

Not every species hides in exactly the same way, and some remain buried for longer than others. That variation is normal, so it is best to compare the animal with its own usual behaviour rather than expecting every millipede to act the same way.

How to tell a moult from a problem

A practical way to judge the situation is to look at what the millipede has done before and after burrowing. If it disappeared into suitable substrate and later reappears, it may simply have been moulting or resting. If it is exposed on the surface, looks dry or damaged, or is in poor conditions, that is more concerning.

For a more detailed comparison, see Is My Millipede Dead or Moulting?. If you are still unsure after reading that, the guide Should You Dig Up a Buried Millipede? explains why digging is usually a bad idea.

Why buried millipedes should not be disturbed

During a moult, the millipede is at its most vulnerable. The new body is soft and needs time, darkness and stable humidity to complete the process safely. Digging it up can interrupt that process, cause stress and expose it before it is ready.

As a rule, if a millipede has buried itself and the enclosure is otherwise stable, it is better to leave it alone and let it finish what it is doing.

What to expect from a moulting millipede

• It may bury itself or become less visible for a period of time.


• It may stop feeding briefly or seem less active.


• It can appear pale or soft after shedding the old exoskeleton.


• It should be left undisturbed while the new body hardens.

Once the millipede has finished hardening, it will usually return to normal movement and feeding.

In summary

Millipede moulting is a normal stage of growth: the old exoskeleton is shed, the new body is soft for a while, and the animal often stays buried until it is ready to emerge. The key is to provide a deep, stable, moist enclosure and avoid unnecessary disturbance.