Some authorities group this order with the Thysanura. The diplura in the U.K. are usually less than 5 mm long. The young and adults look alike. They are pale coloured and feed on decaying plant material. Their antennae tend to be more robust than those of the Thysanura. There is just one family in the U. K., the Campodeidae (see left), of which there are 12 species. Most diplura are found in warmer or even tropical climates.