A Glimpse
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Scientific Name: Analocostreptus gregorius (formerly Spirostreptus gregorius, also previously sold as Spirostreptus sp. 2)
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Family: Spirostreptidae
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Origin: Angola (also recorded in the Democratic Republic of the Congo)
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Adult Size: 10–12 cm
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Lifespan: 1–2 years
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Difficulty: Easy — one of the most beginner-friendly tropical millipedes available
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Temperature: 20–27°C
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Humidity: 65–75%
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Activity: Mostly nocturnal, but semi-arboreal and often visible on the surface during the day
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Diet: Leaf litter, rotting wood, vegetables, fruit, lichen, moss, fish flakes
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Supplements: Cuttlebone, crushed limestone, or oyster shell for calcium
African Olive Millipedes: Overview
This is one of the best beginner millipedes you can get, and it's arguably more interesting to watch than the species that usually get recommended first.
Analocostreptus gregorius is a medium-sized Spirostreptid from Angola — a slender, fast-moving millipede that reaches around 10–12 cm as an adult. The common name comes from their colouration: a distinctive olive-green to olive-brown that you don't often see in captive millipedes. They're a genuinely good-looking species, and the slim body shape gives them a quite different appearance to the chunky, rounded profile of something like an African Giant.
What really sets them apart from a lot of millipedes, though, is their behaviour. Most millipedes spend the majority of their time buried in the substrate, which means you set up a nice enclosure and then rarely see anything in it. African Olives are different — they're semi-arboreal and tend to stay on the surface, climb on cork bark and branches, and generally be visible far more than most species. They're also noticeably fast movers, which makes them more engaging to watch than the slow-plodding giants. For a display enclosure, they're hard to beat.
A Note on the Name
The taxonomy of this species has been through a few changes. You'll see it sold under three names: Analocostreptus gregorius (the current accepted name, reclassified in 2023), Spirostreptus gregorius (the previous name, still widely used in the trade), and occasionally Spirostreptus sp. 2. They're all the same animal.
There's also a common name issue worth knowing about. "African Olive Millipede" is used for this species, but it's more commonly associated with Telodeinopus aoutii — a completely different, much larger millipede. If you're Googling care information, make sure you're looking at the right species. The scientific name is the reliable way to check. Care is broadly similar for both, but they're different animals with different adult sizes and slightly different requirements.
Enclosure and Substrate
A plastic storage box or faunarium works well. These are medium-sized millipedes, so something around 30x20cm with a secure lid is fine for a small group. Because they climb, a bit of height is useful — and make sure the lid fits properly, because juveniles in particular are good at finding gaps.
Substrate depth matters. It should be at least as deep as the length of your longest millipede, because when they moult they burrow down into the substrate and stay buried for about a week while their new exoskeleton hardens. If the substrate is too shallow, they can't moult safely.
Use a mix of organic topsoil (pesticide-free, fertiliser-free) with plenty of crumbled rotting hardwood and dried leaf litter mixed through — oak and beech leaves are both good. The substrate is a major part of their diet, so quality matters. Add a layer of whole leaves on top, along with pieces of cork bark for hides and climbing surfaces. A few branches or twigs at angles give them something to climb on and makes the enclosure more interesting to watch.
Keep the substrate damp but not waterlogged. Mist as needed. These are reasonably adaptable on humidity — 65–75% is the target range, but they're not as fussy as some tropical species.
Good ventilation is important. A few holes in the lid or a mesh vent section will do. You want fresh air moving through without drying things out too quickly.
Temperature
20–27°C. In a typical UK house, you'll probably be at the lower end of this without supplemental heating. A heat mat on a thermostat attached to one side of the enclosure will bring things into the ideal range, particularly in winter. They'll tolerate normal room temperature, but warmer conditions tend to result in more activity and better breeding.
Diet
The substrate itself — leaf litter and rotting wood — forms the foundation of their diet and should always be available. On top of that, African Olives are good eaters that accept a wide range of supplementary foods. They seem particularly fond of apple and cucumber, but will also take carrot, courgette, melon, and other soft vegetables and fruit. Some keepers offer insect jelly as a treat.
Protein should be offered once or twice a week — fish flakes or fish food pellets work well.
Calcium is important for healthy exoskeleton development. Keep a piece of cuttlebone, some crushed limestone, or oyster shell in the enclosure at all times. This is especially important for growing juveniles.
Remove uneaten fresh food within a day or two to prevent mould.
Breeding
African Olives breed readily in captivity and are considered prolific once established. Growth rate is on the slower side — juveniles take a long time to reach full adult size, passing through multiple moults over many months. Each moult adds body segments and additional pairs of legs.
Be careful when doing substrate changes: millipede eggs and small juveniles can be hidden in the substrate and are easily missed or crushed. If you're refreshing substrate, do it gradually and check carefully through the old material before discarding it. The same applies during moulting — a moulting millipede buried in the substrate has a soft exoskeleton and is extremely vulnerable to being accidentally squashed.
Cohabitation
African Olives can be kept alongside certain isopod species, which can help with maintaining the enclosure by consuming mould and waste. However, avoid housing them with aggressively prolific isopods like Porcellionides pruinosus or Porcellio laevis, which can overwhelm an enclosure and potentially disturb moulting millipedes. Something like Cubaris species tend to coexist well.
Don't keep millipedes with cockroaches. Cockroaches will eat millipede eggs, and both groups produce a lot of frass, which means you'd need a very large enclosure and more frequent substrate changes.
Handling and Defence
African Olives are generally calm and easy to handle. Lift them carefully — never pull or pinch — and let them crawl onto your hand. Like all millipedes, they can secrete defensive chemicals when stressed, which may stain or mildly irritate skin. Wash your hands after handling and don't touch your eyes.
Being Realistic
At £10 each, these are one of the most affordable tropical millipedes available, and they're one of the easiest to keep. If you've never kept a millipede before, this is a genuinely solid starting point — arguably better than the African Giants that most beginners gravitate towards, since Olives are more active, more visible, easier to breed, and more tolerant of minor care mistakes.
The main thing to manage expectations on is lifespan. These are not long-lived millipedes — 1 to 2 years is typical. That's considerably shorter than some of the larger Spirostreptids. The trade-off is that they breed well, so a well-maintained colony sustains itself, but individual animals won't be with you for years. If longevity is important to you, this is worth knowing upfront.
