If your millipede is hiding more than usual, buried for long periods or not eating, do not assume something is wrong straight away. For many millipedes, burrowing, staying under leaf litter and going out of sight are normal behaviours. This guide will help you separate normal behaviour from husbandry issues and check the enclosure first.

In millipede troubleshooting, the enclosure usually tells you more than a single symptom does. Substrate, moisture, disturbance, feeding and recent changes all matter, and the same behaviour can have more than one cause.

What to check first

Start by comparing what you are seeing now with the animal's usual pattern. A millipede that is buried, inactive or refusing food may simply be settling in, moulting or following its normal routine. If the change is sudden, persistent or clearly different from what you expect, work through the most likely causes below.

Normal burrowing or moulting. Millipedes spend much of their time in the substrate, under leaf litter or inside rotting wood and other cover. They also become very still and secretive before and during moulting, which is one of the most common reasons a keeper thinks a millipede has died. For a closer look, see Why Is My Millipede Always Buried? and Is My Millipede Dead or Moulting?.

Moisture imbalance. Millipedes need consistently damp substrate below the surface, but not waterlogged conditions. If the bedding is too dry, they may burrow deeper, become inactive or avoid food. If it is too wet or stale, they may also move less or retreat to better-ventilated parts of the enclosure. Check the lower layers as well as the surface, because the top inch can be misleading.

Substrate quality. Deep, food-rich substrate is part of the habitat, not just bedding. If the enclosure is shallow, compacted or lacking leaf litter and decaying wood, the animal may have fewer places to hide, feed and moult safely. A millipede enclosure should feel more like a living woodland floor than a display tank.

Disturbance. Frequent handling, digging, major rearranging or repeated checks can make millipedes stay hidden for longer than usual. If the behaviour started soon after a change, that is worth reviewing before anything else.

Feeding issues. A millipede not eating is not always an emergency. Millipedes graze continuously on the organic matter in the substrate, so they do not behave like pets that rush to a visible food bowl. Fresh foods are supplementary. If the animal has stopped taking offered food and the enclosure's natural food base is poor, that is worth addressing. See Why Is My Millipede Not Eating? for a more focused look at this issue.

Common causes to check first

If you are not sure where to begin, review the enclosure in this order: substrate, moisture, disturbance, then feeding. In most cases, the answer will be found there rather than in the animal itself.

If the substrate feels dry in the deeper layers, improve moisture carefully rather than soaking the whole enclosure. The aim is damp, loose, earthy bedding, not sludge or stagnant conditions. If the habitat is shallow or sparse, increase the depth of substrate and add more leaf litter and decaying wood where appropriate. If the animal has been disturbed repeatedly, leave it alone for a while and let the enclosure settle.

If food is spoiling quickly, review airflow and moisture as well as the enclosure's maturity. Fresh fruit and vegetables can be offered as support, but they should not replace a proper detritivorous habitat. See Common Millipede Keeping Mistakes for a broader check of avoidable setup problems.

What to change next

Make one measured adjustment at a time. Changing several things together makes it difficult to tell what helped or hurt.

After any adjustment, give the enclosure time to settle before changing anything else. Look for trend changes rather than one-off activity: is the millipede using the substrate normally, feeding more steadily, or returning to its usual rhythm?

If the evidence still does not point to a clear husbandry cause, avoid guessing and making repeated changes. Troubleshooting is most effective when it is gradual: note what changed recently, make one adjustment if needed, then allow enough time to see a response.

When hiding is normal

One of the easiest mistakes in millipede keeping is treating being out of sight as a problem in itself. For many species, a millipede that feels secure will burrow, retreat under cover and remain hidden for long periods. This is especially common in stable enclosures with deep substrate and plenty of organic material.

If the animal is otherwise healthy and the enclosure is stable, hiding may simply mean the habitat is working. The key question is not whether the millipede is visible, but whether its behaviour has changed in a way that suggests a husbandry issue.