The gnat larva, for example, breathes at the tail-end, hanging head-downwards from the surface-film.
The distribution of the parasites in the gnat is closely connected with the process of digestion.
Mosquito, a gnat, diminutive of mosca, a fly), a term originally applied to many species of small blood FIG.
Jackson groaned, "Because she has the attention span of a gnat."
Before the end of the 19th century this discovery of the blood parasite of malaria was crowned by the hypothesis of Patrick Manson, proved by Ronald Ross, that malaria is propagated by a certain genus of gnat, which acts as an intermediate host of the parasite.
They are the most resistant to unfavourable conditions of environment, and are able, by a process of parthenogenesis, to give rise to ordinary, indifferent forms again, which can repopulate the gnat.
A gnat pupa swims through the water by powerful strokes of its abdomen, while the caddis-fly pupa, in preparation for its final ecdysis, bites its way out of its subaqueous protective case and rises through the water, so that the fly may emerge into the air.
As the common gnat (Culex pipiens), are rarely found away from human habitations; others seldom or never enter houses, but are met with either in more or less open country, or in the recesses of forests and woods.
The gnat, for example, weighs 97,000 times less than the pigeon, and has 40 times more surface; it weighs three millions of times less than the crane of Australia, and possesses 140 times more of surface than this latter, the weight of which is about 9 kilogrammes 500 grammes (25 lb 5 oz.