Many invertebrate keepers today have some sort of millipede in their collection and as a pet in their own right, they are becoming steadily more popular. After a dubious start some years ago, now, they can make an attractive addition to any invertebrate collection.

Millipedes are a very simple organism; a basic description would be ‘a worm with legs’. Their name, ‘millipede’ means ‘thousand feet’, which is, of course, somewhat inaccurate. The greatest number of legs recorded on one millipede was somewhere in the region of 700; typically though, they have anywhere between 100 and 300 as an adult, with two pairs of legs on each segment.

There are many, many different species of millipede available in the pet trade today. Probably the most famous and commonly kept species is the giant African black, frequently called the Mombassa train. There are also various attractive and rare species, such as the bronze from Africa or the yellow and black-banded (or hornet) from Puerto Rico. The species seen in captivity are, however, just a fraction of the world’s millipedes. In the wild, there are something in the region of 10, 000 species of millipede, spread on almost every land mass, from as far north as the top of North America, to as far south as Indonesia.

One item of note is that in the millipede trade names are often incorrect. Many dealers and retailers will give you a scientific name regarding their particular species but it is generally the case that you ignore this, as it is very rarely correct. With the numbers of species in the world, it is very hard to pin down a particular species; many are similar or almost identical to other, and more often than not the only way to distinguish them from each other is to dissect them. Not very useful if you are looking for a living pet!

The best thing to do is ask for a common name or if there isn’t one, then perhaps research on the internet or in books will need to be made. The former is better as publication of new information is faster on the global network by far in comparison to the printed word. Some species, however, are easily identifiable; the Madagascan fire, for example, has distinctive patterning and colours. Such easy identification is rare in the majority of species - so, go by the common name if you possibly can. You must also be aware of species such as the giant black, for with them it is only the geographical origin that separates different species from one another biologically.

Note: when handling millipedes, one must be very careful - if they are dropped, or handled roughly, they secrete a chemical from glands along their sides. If this gets into your mouth or eyes, it stings, and can cause damage (although this is very rare). Always wash your hands thoroughly after handling millipedes.

‘Typical’ millipedes, i.e. those with a cylindrical, elongate body, are relatively easy to care for. They will need some sort of terrarium. This can be a disused aquarium or even a completely plastic rodent tank. This should have 3-4” of potting soil in the bottom, which should be moist (but not wet) at all times. On top of this should be pieces of wood (oak bark is the best to use) for the millipedes to hide under, and a generous covering of sphagnum moss, also moist - this provides them with extra cover, water, and a little extra food if they need it.

The terrarium itself needs to be humid, although take care - research your chosen species, as they may require different levels of humidity, or maybe none at all. To achieve this humidity in an aquarium, plastic wrap should be secured over 70-80% of the top, more if additional humidity is needed. For the African species, it’s usually best to cover more, up to 99% if necessary. In a rodent tank, all the ventilation will be in the form of metal or plastic mesh or grating over an opening at the top. To seal this, plastic wrap should be secured over as much of this as necessary; but be careful - these sort of lids tend to let in more air than a regular aquarium would, so more may need to be sealed off. Do not worry about cutting off too much air - so long as there is a little bit of ventilation - millipedes breath through pores in their sides, and do not breathe all the time - only when their bodies require oxygen do they open the pores and let it in.

One item of equipment that most millipedes require is a heat mat. This should be big enough to heat one half of the terrarium, thereby creating a heat gradient, so that one end is cooler than the other, in case the millipedes wish to escape the heat for a while.

To keep a millipede well-fed, it is best to give them a variety off different food items; fruits and vegetables are best (cucumber in particular is relished by many species). They will also eat oak leaves. Many millipedes tend to leave the food for a while after it is first put in their terrarium - this is to let it go a bit soft, as they have fairly weak jaws.

While this applies to most millipedes, there is a special group that requires particular conditions; these are commonly known as ‘pillipedes’ in the pet trade, or ‘giant pill bugs’. They are similar to the ‘monkey-pea’ or ‘pill’ woodlice which are familiar in gardens. They look a little like flattened millipedes, and can roll into a sphere when they feel threatened. Pillipedes require very special care, and are generally more suited to the expert keeper because of this. Novices should certainly never attempt to keep these species until they have more experience in this area.

A pillipede’s terrarium should be of a similar setup to a normal millipede’s, i.e. 3-4” of soil, with sphagnum moss and oak bark. Certain aspects of the normal set-up, however, need to be amended. For instance, there should be plenty of rotting oak bark available, as well as a plentiful supply of oak leaves, as they do not apparently eat anything else - not even the always-popular cucumber! They should be kept moist, but not too humid, although some humidity is good. These species dislike too much heat and they are best kept at 70ºF (21ºC). The longest anyone is reported to have kept these alive is six months. They are also extremely difficult to breed and raise. Only three reports of this are known, but as none of these can be proved, whether they are true remains in doubt.

There are three varieties of pillipede available on the market today - the emerald, the chocolate and the black. These, along with a large range of attractive typical millipedes, all come from Madagascar. Pillipedes can be kept with these millipedes, as their habitat is the same, and they are noted to cohabit well. They mix particularly well with the Madagascan fire millipede, a very beautiful millipede which has a bright red upper body, a black lower body, and yellow/orange legs. This species is thought by some to be the most beautiful millipede in the trade.

At some point, whether for money, curiosity or enjoyment, many millipede keepers turn to breeding their pets. Of course, sometimes this just happens naturally - a keeper will have all their millipedes together (at least in species tanks), or (as I like to) in origin tanks - i.e. Africa, America, etc. If the millipedes are naturally breeding well, it can be taken as a sign that conditions are good for that species.

The first thing to do before you start breeding millipedes, and the most obvious, is to make sure you have both males and females of your chosen species. This is best determined by placing the animals in a clear glass container - a bowl is good - so that you can observe them from the underneath without having to try and lift them, when they inevitably curl up and you become frustrated. As the millipedes crawl along the bowl, they will try and climb out and this is when to sex them. When they will crawl up the sides, the curvature of the bowl will cause them to bend backwards, exposing their legs more clearly.

When viewed from underneath, a female millipede has a continuous line of legs, two pairs to a segment, from her penultimate segment to around her third, behind her head. The female will show no break in the pattern at all. A male, however, will have either a gap in this line at his third pair of legs, or he will have a pair of ‘legs’ that look deformed and stumpy, and a bit off-colour. These are the male’s ‘gonopods’, and are what he uses to transfer his sperm to the female. Another way to tell, although it only applies to a few species, is to look at the whole millipede; some are sexually dimorphic, that is, the sexes look different to each other.

A good example of a species which displays sexual dimorphism would be the Tanzanian red-leg. In this species (which breeds well in captivity), the female is a stocky, dull browny-black millipede, with shiny, thin legs. The male, however, is a shiny black-bodied animal, with brighter red legs than the female. The legs of the male are also thicker due to their having extra pads used in the mating process. The males are also marginally slimmer.

During mating, the male millipede will climb onto the female’s back, and crawl over her until he reaches her head. Here, he will rub at her face with his feet, and nibble her with his mouth-parts. This stimulates her to raise her head for mating. At this point, she will rear her head back and he will twist around her (holding onto her all the time) and penetrate her just behind her head with his gonopods. This results in them being locked together. Mating can last for quite some time - anywhere from twenty minutes to an hour or more.

The eggs are laid immediately after mating. In some species, these are laid in a protective dung- ball casing, but in others the eggs are laid as they are - a cream-coloured sphere. The eggs will either be buried, or left scattered around the terrarium. The majority of millipedes will do the former, and a few a mixture of the two. The eggs will hatch in roughly one month but the newborn baby millipedes will probably not be seen for a while after that. This is due to the fact that they remain for the first few moults at the site of laying, constructing little cases from the soil in which to shed their skin. A number of moults later, they will begin to emerge at the surface. Now, they look like tiny maggots; being a white-cream colour, with only a few pairs of legs. At this time they have only one pair of legs per segment, for the first few segments. As they grow, however, they will colour up, harden, and add more pairs of legs and segments.

Baby millipedes are best kept on dry sphagnum moss, which will become moist from food juices, and when too saturated, can be added to, or changed if desired. For any growing millipede, it is essential that their food has a sprinkling of calcium dust. This can be obtained from a pet store or can be extracted from ground-up chalk/cuttlebone if necessary). The calcium is necessary for the growth of the exoskeleton. If you want to be sure what species the babies you have belong to, it may be an idea to set up a separate breeding tank for your desired species so that you can be sure. In a terrarium with several breeding species, it will be very difficult to determine which babies are which.

A brief word should be said at this point on mites. There seem to be two major types - attached, and detached, although neither kind harm the millipede. Mites attached to your millipede, can be removed using a q-tip and water and by gently rubbing the mites off with the q-tip. Never use rubbing alcohol, Vaseline or any other chemicals as these will get inside the millipede through its pores and can make it very sick. The detached mites can be left in situ, as they help to clean up the rubbish in the terrarium.

Finally, a few of the more attractive species to keep are as follows:

The African giant black millipede (Mombassa train) is jet black in colour, grows to six to eight inches long and is very easy to breed. Probably the most commonly seen and kept pet millipede species.

The Madagascan fire millipede has a bright red and black body and yellow legs. It can grow to four inches long and is considered by many to be the most attractive millipede available. This species can be bred in captivity but is not always very easy.

The Puerto Rican yellow and black has a striking yellow and black striped body. It can grow to four inches and is considered easy to breed in captivity.

The Tanzanian red-leg shows sexual dimorphism (the sexes are visually distinguishable). The female is a stocky, dull-looking, browny-black millipede, with shiny, thin legs and the male is a shiny black-bodied animal, with brighter red legs than the female. This species grows to four inches and is considered easy to breed in captivity.

The African bronze millipede has a gentle bronze body, with purple legs. It grows to five inches but none have been bred in captivity to date.