They have strong biting mouthparts and are active and aggressive carnivores, preying mostly on other insects. Dragonflies are also the closest thing the natural world has got to a helicopter. The insects do not simply flap their wings, but twist them back and forth to create a little vortex that lifts the insect.
These dragonfly pictures are taken in my school. All of them are called the Slender Skimmer.
Check out its compound eyes.
These eyes may each contain as many as 30 000 individual lenses. Because of this, dragonflies have exceptionally good eyesight and have been known to respond to movements from more than 40 feet away.