Unlike other millipedes, the Pill millipedes as its name suggests is short bodied, with generally only eleven to thirteen body segments, they are and are capable of rolling into a ball (volvation) when disturbed, this is an effective defence against predators.  The volvation ability has evolved separately in the two orders of the millipede.  An additional defence mechanism is that they can produce a liquid that is both may be both caustic and toxic, to repel predators. Pill millipedes are detritivorous, which means that they feed on decomposing plant matter, usually in in woodlands. 

The males and females differ in size, with the female’s length being 8 to 20 mm, and the males shorter at a length 7 to 15 mm. The millipede is usually shiny black with pale edges to each tergite. In common with a Pill Woodlouse, it can curl up into a pea-like ball if threatened, but not a complete sphere like the Pill Woodlouse. It is similar in appearance to the Pill Woodlouse but has two legs per segment.  In comparison the Pill Woodlouse is similar but only has one pair of legs per segment.   The pill millipede prefers calcareous soils, and can be found amongst leaf litter in woodlands, fields and hedgerows. It also shows a preference for humid areas, such as below logs and stones.  The millipede is found all year round and can be quite active a night, the species is common and widespread in Britain

All year round., being most common in the areas of Rutland and Leicestershire.