Great variety of habitats: Insects thrive well under varied conditions.
4.
Long geological history: Insects were known to occupy this earth for more than 350 million
years, which is a good track record. This has given the insects great variety of adoptions
under different conditions.
Reasons for dominance
1. Capacity for flight: Insects posess wings, which is the lateral extension of exoskeleton.
Insects are the earliest animals and the only flying invertebrates. Flight is used for the
following purpose.
i.
To seek food, mate, shelter and oviposition sites
ii.
To colonize in a new habitat and also to exchange habitat.
iii.
To escape from enemies and unfavourable conditions.
iv.
To migrate (i.e. for long distance travel e.g. Locusts)