The majority of insects are inhabitants of land. Especially many insect species are found in the tropics. Insects occur also inside the Arctic and Ant-arctic Circles, though in these regions they are active only during short summer period.
Insects can be found also high in the mountains and in absolutely waterless deserts. For example, in the Namib desert in South Africa, where there are never rains and there are no plants, live darkling beetles (Gonopus, Syntyphlus subterraneus), feeding only on the scraps of plants brought by wind from distant places (hundreds of kilometers). They obtain the moisture necessary for life in biochemical way: water in their organisms is produced in the process of oxi-dation of dry food!
All areas in crown of trees, all litter of grass, moss, and lichens, and also soil to the depth where roots of plants are present and even deeper are mas-tered by insects. In Turkmenistan, for example, the termite Anacanthotermes ahngerianus burrows to the depth of up to 12 meters!
Many various insects live in caves.
Insects which developed the ability of flying mas-tered the air; the best fliers among them rise to the altitudes of several hundreds meters. However, in-sects can be found even higher: at the altitudes of several kilometers. They are brought here by as-cending currents of air, and then these insects are carried by the wind to very large distances.
Some insects became absolutely aquatic, i.e. breathing by oxygen dissolved in water, for example, walkers (Caraphractus) and fairyflies (Prestwichia aquatica), developing in eggs of true water beetles (Dytiscidae).
Other insects live in water and breathe by the oxygen dissolved in it only at the stage of larva. And at the stage of winged adult, they leave water.
There are insects which, though live in adult stage in water, nevertheless breathe by oxygen in air, rising to the surface.
There are some insects, for example, watermeas-urers (Hydrometridae and Gerridae), who live on water surface, running on it on their long legs. Relatives of our watermeasurers, sea watermeasurers (Halobatidae) in the same way run over surface of seas and even oceans.