Globally the polydesmidans comprise the largest order of the Dip l opoda in terms of described species while in Europe they are outnumbered by the Chordeumatida and even more by the Julida. They are true flat-backed millipedes, their wedge shape allowing them to penetrate between the la ye rs of leaves which they consume in the litter of forests and some other habitats. Polydesmidans also insinuate themselves beneath debris or under dead bark where they may seek shelter. The y are frequendy found beneath fallen branches, logs and other dead wood. Small po lydesmidans easily penetrate into the soil or fragmented rocks and many species inhabit caves: these two phenomena are especially noticeable in arid parts of the South.
