The word ‘millipede’ literally means ‘thousand feet’ – and although millipedes do have a lot of feet, they don’t have a thousand! Millipedes have two pairs of legs per segment, so depending on their size they will have between 200 and 400 feet.
Current estimates place the number of millipede species at 12,00 worldwide; they can be found anywhere that there is damp soil and rotting vegetation to feed on. Several of the tropical species make excellent pets, as they are large, can be colourful, simple to care for and are a good way to introduce children to invertebrate keeping. This care sheet will cover the sort of basic care that is ideal for the most commonly kept millipede species, with more individual data in the species list below.
Enclosures can be plastic or glass, or even wood if it is well sealed with a non toxic waterproof substance. Size is important; any enclosure should be large enough for an adult of the species you are keeping to stretch out fully, and turn around without touching the sides. A good rule of thumb is two millipedes long and one wide – and if you are not using a tight fitting lid, two millipedes high.
There are many good glass enclosures that are available off the shelf, with plenty of space and good ventilation. Avoid using glass fish tanks, as they have very limited ventilation and can lead to stagnant air and anaerobic decomposition in the substrate. If the soil smells like rotten eggs when you clean it out, then the ventilation needs to be improved. As glass loses heat more quickly than plastic or wood, be aware of temperatures. If the enclosure is getting too cool, a small heat mat attached to the side of the enclosure should gently warm one end so that your pet can regulate their own temperature. Don’t put the heat mat underneath; most animals that live on the forest floor will burrow to escape excessive heat, and millipedes simply don’t realise that they need to go up to avoid an over-hot mat.
Humidity is very important. The soil needs to be damp, but not wet; if you squeeze a handful of substrate it should hold its shape, but not drip water. Mixing in some sphagnum or other moss will help to hold humidity, and also prevent the soil from compacting down into a solid, soggy mess. If you then use a thick layer of dried leaves then the soil will stay damp naturally; if you don’t have access to natural leaf litter, then be sure to spray the enclosure regularly to maintain the correct level of humidity.
Millipedes are detritivores; this means that they eat decaying matter, which does make them very easy to feed! They love decaying wood, dead leaves, and will happily take a variety of vegetables and fruit. If feeding fruit, then take care to remove it before it decays, or run the risk of a fruit fly invasion. They also appreciate the occasional soaked dog biscuit, and will nibble on cuttlefish bone when they need to top up their calcium intake. Soft fruits and vegetables like cucumber and tomato are often favourites, and can help to encourage a new millipede to eat.
A bowl of water can be provided, but generally as long as you keep the substrate nice and damp and spray it regularly then it isn’t necessary.
You will sometimes see mites on your millipede, but don’t worry! They live on the millipede’s surface and pick at bacteria and dirt on the animal’s shell, helping to keep it clean. They are totally harmless, but if the numbers get very high you can reduce them by wiping your millipede gently with a damp cloth or soft paintbrush.