Common Giant Millipede Health Issues

Giant millipedes are hardy, and nearly every serious issue in this species traces back to substrate moisture, either too little or, in a couple of specific cases, conditions that stay too consistently wet.

Dehydration

The number one cause of death in this species. Watch for a shriveled, sluggish appearance and dry, cracking segments along the body. Caused by insufficient humidity or substrate that isn't holding moisture properly. Manageable early, raise humidity, moisten the substrate more deeply, and provide a shallow water dish. Stopping it from recurring is a humidity and substrate depth question. Prevention through consistent humidity matters more here than any at-home fix once dehydration is already advanced.

Failed or Incomplete Molt

Often fatal. Caused by low humidity, poor nutrition, or disturbance during the vulnerable molting process. Never assist a molt or attempt to remove shed skin yourself, this can cause real harm. The only effective response is maintaining correct humidity beforehand and leaving your millipede completely undisturbed during the process itself. A burrowed, seemingly unresponsive millipede is very often just molting rather than in distress.

Mite Overgrowth

A heavy infestation shows up as unusually frequent cleaning behavior, thrashing, or visible mite clusters concentrated near the head or legs. Gently wipe affected areas with a damp cotton swab if needed. Never use pesticides or mite sprays, these are toxic to millipedes and can kill the animal you're trying to help. Mites build up on leftover food that sits too long in a humid tank with poor airflow, so clear uneaten food promptly.

The commensal mites that wild Archispirostreptus carry do the millipede no harm, and captive-bred animals don't have them. A new arrival is the other way problem mites get in. A millipede bought to join an established group lives in its own tub with its own tools first, until it has fed, drunk and settled, the same invertebrate quarantine used for tarantulas and every other pet invertebrate.

Exoskeleton Injury

Cracks or lost legs and antennae, usually from a fall or a difficult molt. A cracked segment is the serious one: a damaged exoskeleton can leak hemolymph and let secondary infection in, and either can kill. A millipede with a major crack is worth a vet visit.

Phorid Flies

Small flies that run more than they fly are phorid, or coffin, flies. They breed in dead and decomposing animals, a dead feeder or tankmate, and apart from a handful of reports they do not attack living ones, so a phorid outbreak usually means something in the tank has died. Keep the enclosure lid fine-meshed, remove anything dead promptly, and deal with any fly population in the room before it reaches the tank.

Necrotic Lesions and Soft Exoskeleton

Dark lesions point to substrate that's swampy and poorly ventilated, worth correcting immediately. A soft, weak-feeling exoskeleton points to calcium deficiency, add a genuine calcium source like cuttlebone or crushed oyster shell to the enclosure, not chalk, which isn't an appropriate calcium source for this species.

When a Vet Visit Makes Sense

Few vets treat millipedes, but an exotics practice that sees invertebrates can advise on safe mite control and look at an injury or a failing animal. The millipede travels in a ventilated container with several inches of its own substrate to hold humidity, kept warm and out of direct sun and drafts. The container rules are the same ones that keep any invertebrate safe on the road, set out in the invertebrate travel and transport guide.

The Husbandry Pattern Worth Remembering

Low humidity drives both dehydration and failed molts, the two most serious problems on this list. Soggy substrate and stale air cause the opposite set of problems: mite build-up and necrotic lesions. And falls, entirely preventable through careful handling, cause most physical injuries. Get the moisture balance right and most of this list never happens.

Sources & Further Reading