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 Habitats
Bugs live just about everywhere! Some can survive searing heat, and others
freezing cold, and they dominate just about every landscape on Earth.
On Land
About 97% of known insects live on land. Most species occur in the tropical
and temperate regions, but they can be found anywhere from sea level to high up
in the Himalayan Mountains. They live in a greater variety of habitats than any
other group of animals: rainforests, deserts, woodlands, wetlands, caves,
grasslands and our own backyards. Bugs have even been found in the Antarctic.
The warm and wet environments of rainforests support an abundance of bug life.
Forest floors teem with still uncounted species of insects. The relative
stability of these habitats, developed over millions of years, has enabled
insect species to find their own specific niches in the environment.
In Freshwater
Bugs live in ponds, lakes, streams and rivers and even in small amounts of
water, such as in tree holes. Some bugs spend almost their entire lives in the
water, leaving only to fly from one pond to another, or to pupate.
Most aquatic bugs, like the diving beetle, have to continually return to the
surface of the water to breathe. Other insects have gills and can extract
oxygen from the water. The gills of stoneflies and mayflies enable them to live
at the bottom of streams, where they cling to rocks and other objects using
tiny claws. Some species of stoneflies can live at depths of almost 100 metres.
Many insect larvae live underwater then take to the air as adults. Dragonflies
lay their eggs on waterweeds by the edge of streams. The eggs are surrounded by
jelly and form sticky masses on plants for several days. After the eggs have
hatched, the larvae may remain underwater from two to four years. During this
time they moult up to 15 times. When they are big enough, the wingless larvae
crawl up plant stems out of the water. They then split their larval skin for
the last time to emerge as beautiful winged adults—but with only about six
weeks left to live.
In the Sea
A few species of insects live in marine tidepools and 5 species, the ocean
striders, live exclusively on the surface of the ocean. Crustaceans such as
crabs, prawns and crayfish dominate the oceans, rather than insects. They swam
the seas long before insects evolved.
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