Black Millipede
Blaniulus guttulatus
Pill Millipede
Oxidus gracilis
Polydesmus angustus

Millipedes belong to the class Diplopoda and are generally elongate arthropods with two pairs of legs on each body segment. They are relatively slow moving animals and feeding on living and dead plant matter. The body segments are essentially circular in cross-section, but some of the flat backed millipedes appear flat because some of the segments have flat extensions on the upper surface. Of the 8000 or so species known to science, less than 50 live in the British Isles.

With the exception of the Pill Millipede, these animals are long and slender. The head is short and rounded and it carries a pair of antennae which are somewhat clubbed. These are sharply angled in the middle and they are constantly tapping the ground for scent signals while the animal is moving about. There may or may not be a number of simple eyes, depending upon the habits of the animal: those species that live permanently under the ground generally have no eyes. There are some simple jaws on the underside of the head but, being vegetarians, the millipedes have no poison claws such as we see in the Centipede. Behind the head there is a fairly broad shield-like segment without any legs and this is followed by three segments with only one pair of legs on each. Most of the other body segments have two pairs of legs, but there are a few leg-less segments at the hind end. The hindmost region of the body is called the Telson.

The body segments are basically cylindrical, as mentioned above, and each is covered by a tough cuticle which is usually impregnated with calcium (Ca). The animals are therefore much more common in lime-rich soils. The cuticle of each segment is composed of a markedly domed upper shield or tergite, together with two smaller side plates and a sternite on the lower surface. These four plates are often fused together to make a rigid cylinder. The cylindrical nature of each segment is obscured in the flat backed millipedes, for here the upper regions of each tergite are drawn out sideways to form prominent 'wings'. Each millipeed tergite slightly overlaps the one behind it, and there is a simple ball and socket joint between neighbouring rings. These features give the body considerable flexibility and allow many of the millipedes to coil up. The number of body segments between and within the various species, but the British species rarely have more than 60 segments.

Each sternite carries a two pairs of tiny breathing pores which open into the animals breathing tubes or tracheae. Many millipedes also possess stink glands which open on to the lower surfaces of most of the body segments. The stink glands release pungent fluids containing substances such as Chlorine (Cl), Iodine (I), and Hydrogen Cyanide (HCn). These fluids repel many of the millipedes enemies, and they may also exert a disinfectant effect to keep the body free of infection, bacteria and fungi. The secretions of our native millipeeds are not harmful, but some of the large tropical species are very unpleasant. Some of them actually fire out fluids which can burn the skin and cause blindness if they get into the eyes. Some small millipedes, not normally found in the garden, are clothed with irritating hairs instead of having poison glands.

Millipedes are very much ground-living animals, except for a couple of species, finding their food amongst the leaf litter and soil. They are usually active at night , when the air is cooler and more humid. Like similar animals, they only come to rest in moist areas. Dry weather causes them to move downward through the soil until they reach a more moist area. Although each leg is rather small and delicate, the combined thrust of perhaps more than 100 pairs is remarkably powerful and the millipeeds have no difficulty forcing their way through the soil.

Their rather weak jaws indicate that the millipedes feed mainly on soft or decaying tissues. They usually feed on fungi and dead leaves, but they will consume dead animals as well. They are attracted to the decaying matter and they are especially numerous in garden compost heaps and in heavily manured soils. Some of them play a useful role in helping to speed up the breakdown of decaying material and the return of minerals to the soil. Several species can be found in ants' nests, where they probably assist the ants by consuming scraps of food and other debris. Some millipeeds , notably the spotted snake millipede are serious garden pests because they attack the roots and other parts of crops. Such attacks are most frequent during periods of drought, and it is thought that the millipedes attack the crop primarily for the moisture they contain. When once the plant have been damaged however, the seepage of sap and the inevitable decay of the damaged tissues all serve to keep the millipedes in attendance. Potatoes are often found with numerous millipeeds inside them, but it is unlikely that the millipeeds will attack sound tubers. They probably invade only those tubers which have had the skins damaged by other pests or by fungal infection.

Although most millipede species secrete repellent fluids, they are not free from predators. They are eaten by certain spiders, by frogs and toads, and by birds and small mammals. Toads and birds seem to be the major enemies, and starlings seem to be particularly fond of millipedes, in fact investigations have shown that millipedes can make up more than 50% of a starlings' diet in the spring, but shown to lower during the rest of the year. The millipedes repellent fluids are obviously not that unpleasant as far as the starling is concerned. The ability to coil up into a tight spiral, or even a complete sphere, gives the animals further protection against some of their smaller enemies because the coiled-up animals are often too large for the predators jaws. Some of the tropical millipedes can coil up into balls the size of golf balls...FOOOOUR..!!

The British species of millipedes lay their eggs during the summer and , although some species abandon their eggs naked in the soil, the majority give them some form of protection. This protection may be simply a coating of saliva or some other glandular secretion which picks up soil particles and thus camouflages the eggs. Some millipeeds actually coat their eggs with excrement before abandoning them, while many others actually make nests for the eggs. These nests may be constructed in hollows in the soil, under stones or bark, or in rolled up dead leaves. The females own excrement is nearly always used in the construction of the nest, moistened with saliva or other fluids so that it can be worked like mortar. Some millipedes exude silken threads which are used in nest building. The female may abandon her nest when once she has laid her eggs and covered them over, but some species, notably among the flat backed millipedes, remain with their eggs for several days. You may well find one of these females coiled around her nest if you lift up damp logs during the summer.

The young millipedes emerge from their eggs in a few weeks, but they do not look much like the adults. They are short grub-like creatures with only three pairs of legs and only a few body segments. They have to undergo several moults or skin changes before they reach maturity, and they add a number of segments and several pairs of legs at each moult. Moulting is a rather dangerous business for any insect because it leaves the animal in a soft helpless state for a while, but many young millipedes protect themselves at such times by building little nests, rather like those in which the eggs were laid, and remain there until the moult is completed. Millipedes may live for anything between a few months to a few years depending on the species. The adults of some species, particularly those living in cooler regions, exhibit an interesting alternation of fertile and non-fertile stages. The reproductive organs are functional when the animals first mature, but the animals moult again after the breeding season and the reproductive organs become inactive. They remain inactive throughout the winter, but the animals then moult again and revert to the sexually active stage. Some millipedes have been known to pass through at least four sexually active stages.


Millipedes are quite common in warehouses and outside stores, and while not a pest in the true sense of the word of doing damge in the household (except to gardeners in the garden) there is the risk of product contamination, be it finished goods or goods that will be used in manufacture. With the large number of greenfield sites, the risk is greatly increased, hence it is likely that a preventative contract would be advisable where a spray treatment to wall/floor junctions could be carried out every 3 months. From experience it has been found that a water based alphacypermethrin is very good and, as long as the areas aren't too damp, and will give a good residual effect. Obviously alpha is quite expensive and thought may be given to the use of fenitrothion or diazinon as long as there is no chance of taint, for as we know these latter two products have quite an odour to them but the residual is very good. A very good product is Ficam, which is manufactured by Agrevo. This is a Bendiocarbamate and acts on the nervous system, in fact it is like nerve gas in powder form, indeed the antidote is Atropine Sulphate, the same as that in the syringes for the armed forces. All of this sounds powerful stuff, which it is as the powder is 80% before mixing, but once mixed to the correct ratio with water there is no problem....eeeeeexcept....for cats!! Cats are very susceptible to this insecticide and great care should be taken if there are cats on the premises. At top of my main page is a link to Russellipm, this a company that provides alternative methods of pest control using pheremones (insect smells) and suchlike.

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© Stuart M Bennett 2000