Animals that obtain nutrients by eating detritus which is dead animal and plant parts are called detritivores (1). They ingest the nutrients. Examples of detritivores are earthworms, slugs and snails, millipedes, dung beetles and the larvae of beetles and flies.
On the other hand, organisms that break down dead plants and animals into substances that plants need to grow are called decomposers. They absorb the nutrients. Examples of decomposers are fungi and bacteria (2).
Millipedes are invertebrates which means they have no backbones or internal skeletons. There are three species found in Ireland: The Flat-backed millipede (Polydesmus angustus), the Pill millipede (Glomeris marginata) and the White-legged snake millipede (Tachypodoiulus niger) (3). This is the commonest millipede in Ireland. In Irish all millipedes are called Mílechosaigh (4).
Mil means a thousand in Latin and at first glance they seem to have that many legs! They haven’t got even near this figure, however. Some do have as many as 300! Ped means a foot in Latin.
Millipedes have two pairs of jointed legs on each segment. (In contrast, centipedes have only one pair of legs in each segment). They lift each pair of legs at the same time as they walk.
They feed on dead leaves or leaf litter and rotting plants and are useful recyclers. They in turn are eaten by pygmy shrews, spiders and birds. Pill millipedes curl into a tight spiral when they feel threatened. This protects their soft underparts.
Centipedes or Céadchosaigh in Irish are carnivores and not herbivores like the millipedes. They prey on spiders, worms, slugs and flies.