- Scientific Name: Ophistreptus guineensis
-
Common Name: African Giant Chocolate Millipede
-
Family: Spirostreptidae
-
Origin: West Africa — Ghana, Nigeria, and surrounding regions (dry savannah habitats with distinct rainy and dry seasons)
-
Adult Size: Up to 25–26 cm — this is a large species
-
Lifespan: 7–10 years with good care
-
Difficulty: Easy — hardy and forgiving
-
Temperature: 24–28°C (can tolerate higher, up to 30°C)
-
Humidity: 60–80% — notably drought-tolerant for a tropical millipede
-
Activity: Surface-active, good climbers, often visible during the day
-
Diet: Leaf litter, rotting wood, fruit, vegetables, moss
-
Supplements: Cuttlebone, crushed limestone, or oyster shell for calcium
Chocolate Millipedes: Overview
The Chocolate Millipede is one of the larger species available in the UK hobby, growing up to 25–26 cm as an adult. The name is straightforward — they're a rich, warm chocolate-brown to reddish-tan colour throughout, with a glossy sheen that catches the light. They closely resemble Archispirostreptus gigas (the African Giant Black) in overall body shape and proportions, but where the AGB is dark and sometimes a bit dull-looking, Chocolates have a warmth and lustre to them that makes them genuinely striking.
They originate from the dry savannah regions of Ghana and Nigeria, which makes them notably different from many tropical millipedes in one important way: they're drought-tolerant. In the wild, they experience distinct dry and rainy seasons rather than constant tropical humidity. This translates into an animal that's more forgiving of humidity fluctuations in captivity than many other species — which is a significant advantage for less experienced keepers or anyone who sometimes forgets to mist.
Like the Ghana Speckled Legs (T. aoutii) that we also stock, Chocolate Millipedes are active and surface-dwelling. They'll climb on branches, cork bark, and enclosure furniture, and they spend a lot of time above ground rather than permanently buried in the substrate. Combined with their size, this makes them one of the more visually rewarding millipede species to keep.
Enclosure
These are large millipedes and they need space. A minimum enclosure size of 60x20 cm floor space is the baseline, but bigger is better, particularly if you're keeping a group. A large plastic storage box with ventilation, a converted aquarium, or a glass terrarium all work.
Provide thick branches for climbing — Chocolates will use them. Cork bark pieces, both horizontal and angled, give hides and climbing surfaces. The enclosure should be secure, especially if you're keeping juveniles, which are smaller and better at escaping than you'd expect.
Ventilation is needed but doesn't have to be as elaborate as for some humidity-sensitive species. A few ventilation holes or a mesh section in the lid will do.
Substrate
Depth should be at least 10 cm, ideally deeper for adults — the general rule with millipedes is substrate depth at least equal to the animal's body length for safe moulting. For a 25 cm millipede, that's a serious depth of substrate, so factor this into your enclosure planning.
Use organic topsoil (pesticide-free, fertiliser-free) mixed with crumbled white rotten hardwood and dried leaf litter. Oak and beech leaves are both good. The substrate forms a major part of their diet — they eat it — so this isn't just bedding, it's food. Top with a thick layer of whole leaves, moss, and additional pieces of soft rotting wood.
Keep the substrate moist to the touch but not saturated. These millipedes are more tolerant of drier conditions than many species, but they still need access to moisture. Their mouthparts aren't strong enough to chew hard, dry material — humidity keeps the wood and leaves soft enough for them to eat. A completely dry substrate means they can't feed properly, even if there's plenty of organic material available.
Temperature and Humidity
24–28°C is the target range, with some sources recommending up to 30°C. These are warm-climate millipedes that appreciate higher temperatures than some other species. In a UK house, a heat mat on a thermostat will almost certainly be needed. As with all burrowing millipedes, place the heat mat on the side of the enclosure above the substrate line, never underneath.
Humidity should be maintained at around 60–80%. The drought tolerance of this species gives you more margin for error than with something like Centrobolus, but don't take that as permission to let things dry out completely. A moderate level of misting — once every few days, or when the top layer of substrate starts drying — will keep things in the right range.
Diet
Chocolate Millipedes are enthusiastic and unfussy eaters. The substrate (leaf litter and rotting wood) is their primary food and should always be well stocked. On top of that, they'll happily take a wide range of fruit and vegetables. Favourite foods from keeper experience include cucumber, melon, banana, oranges, and cooked sweetcorn.
Moss and lichen are also eaten and appreciated.
Calcium should always be available — cuttlebone, crushed limestone, or oyster shell. This is especially important for growing juveniles and breeding females.
Protein can be offered occasionally — fish flakes or similar.
Remove uneaten fresh food within a day or two to prevent mould.
Breeding
Chocolate Millipedes will breed in captivity, but there's a detail worth knowing: breeding often seems to be triggered by simulating seasonal changes. In the wild, these animals experience dry periods followed by wet periods, and replicating this cycle — allowing the enclosure to dry out slightly for a few weeks, then increasing misting and humidity — can stimulate egg-laying.
Males can be identified by the modified legs (gonopods) on the seventh body segment. Mating is conducted face to face, and pairs can remain coupled for extended periods.
An important point about the young: leave them with the adults. Juvenile Chocolate Millipedes feed on the frass (droppings) of the adults, which provides them with essential gut bacteria they need to properly digest their food. Separating them too early can be detrimental.
Sexing
Males have their legs on the seventh body segment replaced by gonopods — specialised reproductive structures that are tucked into pouches. On females and immature animals, the seventh segment has normal legs. This is the most reliable way to sex any Spirostreptid millipede.
Handling
These are calm, gentle millipedes that tolerate handling well once accustomed to it. They're not aggressive and won't bite. When startled, they'll either walk backwards toward cover or curl into a defensive coil. Like all millipedes, they can secrete defensive chemicals — and Chocolate Millipedes are reportedly noted for producing a faintly chocolate-like scent, which is where some people trace the common name from (though the colour is the more obvious explanation).
Wash your hands after handling. The secretion can stain skin temporarily and may irritate sensitive areas.
Lifespan and Expectations
This is where Chocolate Millipedes really stand out. With good care, they can live 7–10 years — significantly longer than many other commonly available species. That's a genuine long-term commitment, but it also means you get more from the relationship than with shorter-lived species. A well-maintained group can provide years of observation and breeding.
Growth is slow. Juveniles go through many moults over a long period before reaching adult size, doubling their length along the way. Don't expect a baby to become a 25 cm adult in a few months — this is a species that rewards patience.
Taxonomic Note
It's worth mentioning that there's some uncertainty in the hobby about whether everything sold as Ophistreptus guineensis is actually a single species. The recorded distribution of O. guineensis according to scientific databases doesn't always match the collection localities reported in the hobby (Ghana/Nigeria/Cameroon), and it's possible that multiple species within the genus are being sold under the same name. For practical keeping purposes this doesn't change the care advice, but it's an honest reflection of where the taxonomy currently stands.
