Ivory Millipede Care Guide (Chicobolus spinigerus)

The Florida ivory is the millipede most experienced keepers recommend first, and for once the recommendation holds up. It is large without being demanding, it breeds readily, and unlike most of the hobby it spends real time on the surface in daylight where you can actually see it. This is how to keep Chicobolus spinigerus properly, including the several things widely published about it that are wrong.

The short version

Ten centimetres of substrate minimum, made mostly of rotting hardwood and leaf litter, kept damp underneath and allowed to dry a little on top. Room temperature. Permanent calcium. No heat mat. Then leave it alone, particularly when an animal has buried itself.

How big they actually get

Seven to ten centimetres is the honest adult range, with well-grown animals from some lines reaching a little over twelve. You will see "16cm and up" quoted in places. That figure is not supported anywhere else and belongs to Archispirostreptus gigas, the African giant, which is a genuinely different proposition. If you are choosing a species on size, choose on the real number.

They grow fast by millipede standards, reaching maturity in roughly eighteen months. Hatchlings emerge with three pairs of legs and add segments and legs at each moult, so a juvenile looks like a different animal from its parents for a long time.

Temperature: subtropical, not tropical

This is the correction that matters most for UK keepers. Ivories are routinely sold as a tropical species needing supplementary heat. They are not tropical. They range from peninsular Florida up through Georgia into South Carolina, where winter nights are genuinely cold, and they keep perfectly well at ordinary UK room temperature.

Around 21 to 25C is comfortable. At 20C they are fine and simply less active. You will also find a claim that they die rapidly below 21C, which traces back to a single keeper report that the source itself hedges, and which cannot be squared with the climate across their native range. Do not buy a heat mat on the strength of it. Under-tank heating is actively unhelpful here, because it dries out the deep layer these animals moult in.

Substrate depth is most of the husbandry

Ten centimetres is the working minimum and fifteen is better if you want them to breed. A useful rule of thumb is that the substrate should be at least as deep as your longest millipede is long.

The reason is moulting. An ivory burrows down, hollows out a chamber, and moults underground, where it lies immobile and completely soft for days or even weeks. Shallow substrate means no chamber, and a failed moult is usually a dead millipede. Depth is not a nicety, it is the single most important number in this guide.

For composition, aim for a majority of decaying hardwood and leaf litter mixed through a coir or topsoil base, with a little sand and crushed cuttlebone or limestone worked in rather than left on the surface. Keep the lower layers damp and let the top dry slightly between waterings. Substrate moisture matters considerably more than the reading on a hygrometer.

Feeding

The substrate is the food. Decaying hardwood and litter are the staple and should never run out, which means topping the enclosure up as it is consumed rather than feeding a millipede the way you would feed a pet.

Where this species differs from most spirobolids is that it takes supplementary food more readily than its relatives. Courgette, squash, pumpkin and similar soft vegetables are genuinely well received. Offer small amounts, remove what is not eaten within a day, and do not let produce become the diet. Overfeeding fresh food is the fastest route to grain mites and mould.

The purple ivory question

People search for "purple ivory millipede" as though it were a separate species. It is not. Chicobolus contains exactly one species, so anything sold as a purple ivory is Chicobolus spinigerus.

There are two different things going on behind the name, and most sellers conflate them. The first is age: juveniles are frequently purple and mature into the familiar black-and-cream banded adult, so a proportion of "purple ivories" simply grow out of it. The second is locality - there are genuine regional colour forms, some of which hold purple or brown tones into adulthood, and some of which mature at a smaller size. If the colour is why you are buying, ask which of the two you are being sold. Whether purple breeds true is not established.

Handling, and the quinone question honestly

Ivories are docile and handle well. Like all millipedes in their group they can secrete a defensive fluid, and it is worth understanding what that actually is.

It is not cyanide. The cyanide story belongs to the flat-backed millipedes and gets transplanted onto every other species constantly. Ivories produce benzoquinones instead. On skin these cause a brown stain that can last days to weeks and resists washing, sometimes with mild irritation. That is the realistic worst case from ordinary handling, and it is a nuisance rather than a danger.

The real risk is the eyes, where quinones can cause genuine chemical injury. So: handle low over a surface, never restrain or startle an animal, put it down if it coils, and wash your hands afterwards before touching your face. Supervise children rather than banning them. There is no bite, no sting and no venom. Our piece on whether millipedes are dangerous covers the wider question.

Moulting: the one rule that kills animals

A millipede that has buried itself, or that is coiled and unresponsive, is very likely moulting. Leave it completely alone. Do not dig it up to check, do not move it to another enclosure, and do not handle a millipede that has recently surfaced looking glossy and soft.

This is not theoretical caution. Keepers have documented ivories dying from injuries caused by nothing more than being gently picked up shortly after a moult, with the damage mistaken for disease afterwards. A coiled millipede is a healthy millipede that wants to be left alone.

Breeding

Ivories are among the easiest millipedes to breed, which is a large part of why they are recommended to beginners. Mature animals pair face to face, and the female burrows to build a nest, encasing each egg in a capsule of soil and her own droppings. Eggs typically hatch in around three to six weeks, though longer is possible.

Clutch size is reported anywhere from around sixty to a hundred depending on the source, and the higher figures circulating should be treated with caution. Both sexes mature well below full adult size, so you do not need maximum-sized animals to get offspring.

Two practical points. Keep juveniles with the adults, so they can acquire gut microbes from adult droppings - this is standard millipede practice and it matters. And be aware that captive-bred stock establishes far more reliably than wild-caught imports, which is where most reported breeding failures come from.

Can they live with isopods and springtails?

Springtails, yes, without reservation. Add them.

Isopods are genuinely disputed and anyone telling you it is settled is overstating their case. Some breeders report isopods nibbling freshly moulted millipedes and taking eggs and hatchlings, occasionally with severe losses. Others have kept the two together for years without incident and point out that no study supports the predation claim either way.

What both camps agree on is that the risk is species- and density-dependent. Fast-breeding, protein-hungry Porcellio and powder isopods are the ones implicated. Dwarf whites and Armadillidium are described as much lower risk. The danger is concentrated on moulting animals, eggs and young, not healthy adults. If you are actively breeding ivories, springtails alone is the cautious call. If you want a mixed setup, keep isopod density low and keep them well fed.

Keeping them in the UK

There is nothing preventing you keeping or selling this species in the UK. It is not CITES-listed and it does not appear on the invasive species lists for England and Wales.

One obligation does bind you, and it is worth stating plainly: releasing any non-native species into the wild is illegal under the Wildlife and Countryside Act 1981. If you can no longer keep a colony, rehome it. Buying UK captive-bred stock also sidesteps the import questions entirely, and gives you animals that are already acclimatised.

If you are new to millipedes generally, our general millipede care guide is the place to start, and the UK millipede identification guide covers the species you will find in your own garden. The full range is in our millipedes collection, and our ivory millipedes are captive-bred.