Matt Black Millipedes ( Treptogonostreptus Intricatus)

The Giant Matt Black Millipede (Treptogonostreptus intricatus) is one of the most striking large millipedes in the hobby — a substantial Central African detritivore that rivals the famous African Giant for sheer size, reaching up to around 25 cm (roughly 10 inches) as a full adult. Where its giant cousin is glossy, this species earns its name with a deep, velvety matt-black finish that catches the light quite differently. Add a calm temperament, a genuinely long lifespan, and a willingness to settle into a bioactive setup, and you have a flagship invertebrate with real presence.

A quick, honest note on sourcing. The millipedes we have available here are wild-caught imports from Cameroon, as most of this species in the UK hobby are. We'd always rather tell you that plainly than dress it up. The genuine good news is that T. intricatus has an excellent track record of adapting to captivity — keepers consistently find they do really well once settled into a stable, well-ventilated, properly set-up enclosure. And unlike some of the slower large species, this one will often breed willingly for you down the line, so a wild-caught group today can become a home-grown colony in time.

This is still a proper commitment. Adults can live 7–10 years — far longer than most invertebrates — and reach a size that needs genuine space and deep substrate. If millipedes are new to you, it's a forgiving and rewarding species to start with, though the smaller beginners in our millipede collection are worth a look first if you'd prefer to build up to something this large.

Quick Care Summary

• Scientific name: Treptogonostreptus intricatus (Voges, 1878)
• Common names: Giant Matt Black Millipede, Giant Cameroon Millipede, Cameroon Matt Black
• Family: Spirostreptidae
• Origin: Cameroon, Central Africa — lowland forest floor
• Adult size: 20–25 cm typical (up to around 10 inches) — rivals the African Giant Millipede
• Lifespan: 7–10 years in captivity
• Difficulty: Beginner to intermediate — forgiving once the setup is right
• Temperature: 23–27°C (warm tropical)
• Humidity: 70–80% with a proper gradient
• Ventilation: Generous — this species especially appreciates good airflow
• Substrate depth: Minimum 10–15 cm, deeper is better — they burrow to moult and shelter
• Diet: Detritivore — decaying hardwood, leaf litter, fruit and veg, with calcium
• Behaviour: More surface-active than many large millipedes; will explore and rest on the surface
• Source: Wild-caught imports

What Makes the Giant Matt Black Millipede Special

It's genuinely large. At 20–25 cm fully grown, this species matches the African Giant for size — considerably bigger than most people expect from a millipede. A full adult is a properly substantial animal, and the heft surprises first-time keepers every time.

That matt-black finish is the draw. Where the African Giant Millipede is glossy, T. intricatus is a deep, light-absorbing matt black — understated and elegant rather than shiny. Younger animals can show browner tones that darken with age. The appeal here is form and finish, not bright colour.

The longevity is unusual for an invertebrate. Seven to ten years puts this species in completely different territory from most of the hobby. For comparison, a Powder Orange isopod lives 12–18 months and even long-lived Porcellio rarely pass three years. This is an animal that can be part of your household for the better part of a decade.

It's more surface-active than most large millipedes. Many big species spend nearly all their time buried, but T. intricatus is reasonably willing to explore and rest on the surface, so you actually get to see it — a real plus for a display animal.

The temperament is calm and handleable. Like other large spirostreptids, this is a gentle, slow-moving species that doesn't bite or sting. Its only real defence is to coil into a tight spiral, and some individuals may release a harmless but pungent secretion if seriously stressed — so always wash your hands before and after handling.

It's a strong bioactive cleanup species. A full-grown matt black processes leaf litter and rotting wood at a scale smaller species can't match, working happily alongside isopods and springtails in a larger setup.

Setting Up the Enclosure

Give them room. An adult needs a floor area of at least 45–60 cm in length for a single animal or a pair, more for a group. As ground dwellers, horizontal floor space and substrate depth matter far more than height — though they are surprisingly strong, so a secure, well-fitting lid is essential.

Provide several hides — cork bark, half logs, and rounded bark pieces that support burrowing. Decaying wood doubles up nicely as both shelter and food. Keep the enclosure out of direct sunlight.

Ventilation matters more for this species than for some. T. intricatus does noticeably better with generous airflow, so cross-ventilation through mesh-covered holes on opposite sides is ideal — it keeps mould down while the deep, damp substrate maintains humidity. As with all millipedes, skip the standing water dish; they take up moisture from the substrate, and open water is an unnecessary drowning risk.

Substrate — The Critical Component

For this species substrate isn't bedding, it's the foundation of both diet and behaviour. They eat the substrate itself, so quality is everything — get it right and your millipede thrives; get it wrong and even a hardy animal struggles.

Aim for a minimum depth of 10–15 cm, and deeper if you can. They burrow to moult — the most vulnerable moment in their life cycle — and shallow substrate is a leading cause of moult failure.

A reliable mix is roughly half decomposed hardwood leaf litter (oak, beech, magnolia — the dietary backbone), a fifth crumbled rotting hardwood soft enough to break between your fingers, a fifth pesticide-free organic topsoil, and the remainder split between a little sand or fine grit to aid digestion and a calcium source such as crushed limestone, cuttlebone, or eggshell. Some moss worked through the top helps hold moisture. Avoid pine, cedar, and any other conifer entirely — the resins are toxic to millipedes, so it's hardwoods only.

Top the leaf litter up as they work through it; they get through a surprising amount and need constant access for proper nutrition. The Drygoods Mystery Box is a cost-effective way to keep substrate components, calcium, and supplementary food stocked.

Diet

Giant Matt Black Millipedes are detritivores with hearty appetites. The foundation is always-available decaying hardwood and leaf litter, plus soft, well-rotted white hardwood — between them these make up most of the diet. On top of that, offer fresh veg and fruit a few times a week: cucumber, courgette, sweet potato, squash, banana, melon, and apple all go down well, with fruit kept modest because of the sugar. A constant calcium source — cuttlebone, crushed oyster shell, or limestone — is essential for maintaining that large exoskeleton. They'll also take the occasional bit of higher-protein food, but keep it occasional rather than routine.

Humidity and Temperature

Keep humidity around 70–80% with a clear moisture gradient. The substrate should feel damp throughout — like a wrung-out sponge — but never waterlogged. A light mist of the surface plus the occasional deeper watering keeps it where it needs to be, and the generous ventilation this species likes means you'll want to keep half an eye on the damp end not drying out too fast.

Target 23–27°C. UK rooms often dip below this in winter, so a low-wattage heat mat on a thermostat, mounted on the side of the enclosure rather than underneath, keeps a warm end without trapping the millipede against a hot, dry base. Avoid sharp temperature swings and keep the enclosure away from windows and radiators.

Handling

Done properly, T. intricatus is one of the more rewarding large inverts to handle — gentle, slow, and unbothered by careful contact. Let the millipede walk onto your hand rather than picking it up, support its full length rather than dangling it by one end, and keep sessions short. Wash your hands before and after, and leave them well alone while they're moulting.

Two defence behaviours are worth knowing. The first is the harmless spiral coil. The second is an occasional pungent secretion some individuals release from the body pores when genuinely stressed — harmless on intact skin, but worth rinsing off thoroughly, as it can stain temporarily. Most animals never use it at all.

Breeding

This is where T. intricatus has a real edge over some of the larger species: it breeds willingly in captivity. Males and females mate readily and the females deposit eggs in the substrate, often prompted by a slightly drier spell followed by a wetter one, which mimics the seasonal cycle that triggers egg-laying. Males can be told apart by the modified legs (gonopods) on the seventh body segment.

For the best chance of success, give them a stable warm temperature, consistent humidity, deep substrate rich in rotting wood, and plenty of calcium for breeding females. It's well worth leaving the young in with the adults — the juveniles feed on the adults' droppings early on, which seeds their guts with the bacteria they need to digest the substrate. A wild-caught group bought today can, with patience, become a self-sustaining colony.

Who Should Buy a Giant Matt Black Millipede?

They're an excellent fit if you want a flagship display invertebrate with real size and a distinctive matt finish, you're happy taking on a 7–10 year commitment, you'd like a large species that's actually visible rather than permanently buried, or you fancy trying your hand at breeding a big millipede. They also make a great centrepiece in a larger bioactive vivarium.

They're less suited to you if you can only offer a small enclosure, you want a species that stays put and out of sight, or you're set on bold colour — these are a deep matt black, and the size and finish are the visual draw, not a bright palette.

Pair With Springtails and Drygoods

A complete setup usually pairs the millipede with a springtail culture for mould control in the humid enclosure, plus the Drygoods Mystery Box for substrate components, calcium, and food in one go. If you're building broader variety, the Millipede Mystery Box is a good way to add to the collection alongside your flagship.

Realistic Expectations

They get genuinely large. Picture adults of 20–25 cm and plan the space accordingly. Photos online sometimes show smaller juveniles; full-grown animals are properly substantial.

They live a long time. Seven to ten years is typical, so it's worth thinking honestly about whether your housing and circumstances suit a decade-long commitment.

They like air. This species rewards generous ventilation more than most — don't seal them into a stuffy box, and the trade-off is just keeping an eye on humidity.

The colour is understated. Adults are a deep matt black, with younger animals often browner. Elegant rather than vivid — the size and finish are what draw the eye.

Substrate depth and quality are non-negotiable. They eat their substrate and burrow to moult, so give them a deep, hardwood-rich mix from the outset; it's the single biggest factor in keeping them healthy.