is a family of primitive insects
belonging to the order Archaeognatha
(the jumping bristletails). There are around 250 described species worldwide. These insects are wingless, elongated and more or less cylindrical with a distinctive humped thorax
and covered with tiny, close-fitting scales
. The colour is usually grey or brown, sometimes intricately patterned. There are three "tails" at the rear of the abdomen
: two cerci
and a long central epiproct
. They have large compound eyes
, often meeting at a central point.
Machilids undergo virtually no metamorphosis during their life cycle and both nymphs and adults are generally inconspicuous herbivores and scavengers, many species being restricted to rocky shorelines, but some found in well vegetated habitats inland. They can move very fast and often escape by jumping considerable distances when disturbed.