Odonata on the campus of NIT Rourkela

Odonata on the campus of NIT Rourkela

Some facts (Copied from [1] for readers benefit): 

Odonata is an order of carnivorous insects, encompassing dragonflies (Anisoptera / Epiprocta) and damselflies (Zygoptera) .

Odonates are aquatic or semi-aquatic as juveniles. Thus, adults are most often seen near bodies of water and are frequently described as aquatic insects. However, many species range far from water. 

They are carnivorous throughout their life, mostly feeding on smaller insects.

Eggs are laid in water or on vegetation near water or wet places, and hatch to produce pronymphs which live off the nutrients that were in the egg. They then develop into instars with approximately 9–14 molts that are (in most species) voracious predators on other aquatic organisms, including small fishes. 

The nymphs grow and molt, usually in dusk or dawn, into the flying teneral immature adults, whose color is not yet developed. These insects later transform into reproductive adults.

Ref:

[1] http://en.wikipedia.org/wiki/Odonata