Distribution map

Millipedes are a widespread and fairly common group of animals often found amongst leaf litter and under rocks and stones. There are around 10,000 species worldwide, of which less than 50 may be found in the UK.

The flat-backed millipede is one of the most common and easiest to recognise due to their flattened body shape. They may grow up to 20 mm long and have 30 pairs of legs.

Historically, millipedes are the oldest known land animals with fossil records dating back to 428 million years ago. Fossils have also shown a species of millipede believed to be the largest ever land-living invertebrate with a length of over 2.5 metres.

Millipedes are generally slow moving with fairly weak mouthparts as they feed solely on dead and decaying plant material. They are also a good friend to the gardener as they play an essential role in the recycling of nutrients in the soil much like the earthworm.

Unfortunately, the millipede has many predators including insects, spiders, frogs, toads, birds and small mammals. In order to deter these predators, some millipedes have developed their own defence mechanisms. The flat-backed millipede has glands near the back of its body where is can produce the deadly poison hydrogen cyanide. When threatened the millipede will release the toxin which can kill, or at least sicken, any predator that gets too close. To prevent harming itself, the millipede will temporarily close its breathing pores until the toxin has dispersed.

For such a common species, you can see from the map we have relatively few records of the Flat-backed Millipede, probably because they are easily overlooked. However, all species, no matter how small or commonplace, are important to NESBReC and so we would appreciate any records of millipedes that you may find. For example you may come across a few while you are tidying up the garden at this time of year.