Flies, mosquitoes, gnats and midges are the species in this order. In compound names containing "fly" for members of this order, the name is written as two words as in "crane fly". For insects that are members of other orders the name is written as a single word as in "butterfly".
Subdivision
About 85,000 species of insect have only two wings and are classified as members of Diptera, There are two generally accepted sub-orders of Diptera. The Nematocera are usually recognized by their elongated bodies and feathery antennae as represented by mosquitoes and crane flies. The Brachycera tend to have a more roundly proportioned body and very short antennae.
Beyond that, considerable revision in the taxonomy of the flies has taken place since the introduction of modern cladistic techniques, and much remains uncertain. The secondary ranks between the sub-orders and the families are more out of practical considerations than out of any strict respect for phylogenetic classifications. (Modern cladists tend to spurn the use of any rank names.) Several of the classifications used now in this article remain paraphyletic groupings; this is particularly notable in the Orthorrapha.
Family names
Families in the list below marked with a plus sign are extinct.
Flight is the process by which an animal or object which is heavier than air achieves sustained movement either through the air by aerodynamically generating lift or aerostatically using buoyancy, or movement beyond earth's atmosphere, in the case of spacecraft.
Flying tree frogs use greatly enlarged webbed feet for a similar purpose, and there are flying lizards which employ their unusually wide, flattened rib-cages to the same end.
Among living animals that fly, the wandering albatross has the greatest wingspan, up to 3.5 metres (11.5 feet); the trumpeter swan and the great bustard compete for the greatest weight, at around 24 kilograms (38 pounds).
Stable flies are also common in cattle farms and are similar in appearance to house flies at first glance, but can easily be distinguished by their biting habits.
The mouth parts of these flies are formed into a sharp proboscis which can be seen under the head pointing forward, parallel to the resting surface.
The larvae of this species develop in moist vegetable matter often contaminated by animal urine and faeces and therefore will generally be found breeding outside farm buildings and often around the edges of buildings, but in various areas of pasture as well.