Dragonflies are typical of aquatic insects. They are very sensitive to water quality changes, so they are often used as indicator species to monitor water quality changes, which is of great help to human beings. The water quality of the wetland will be tested by dragonflies. You can often see the scene of "dragonfly water". In fact, dragonflies are spawning and breeding in the water at this time.

Dragonflies like wet environment, so they usually fly in ponds or rivers, and their larvae (larvae) also need to develop in water. Odonata is a semi-metamorphosed insect, which has only three stages in its life: egg, larva and adult. Adults often lay eggs in water by skimming. Larvae, also known as hydra, preys on other aquatic organisms in the water, climbs out of the water before emergence, mates and lays eggs, and completes its life history.

Some kinds of female dragonflies will use an extreme strategy to avoid unwanted suitors: they will fall from the sky and pretend to be dead.

Extended data

In the insect kingdom, dragonflies are undoubtedly excellent pilots. It not only flies fast and high, but also can do many difficult actions that modern planes can't do. If the wing eye is removed, the dragonfly's flight will become wobbly.

Inspired by the dragonfly's wing eye, the aircraft designer imitated the dragonfly's wing and added a counterweight at the leading edge of the wing to move the center of gravity forward, thus solving the flutter problem of some aircraft. Aircraft designers have a great feeling of knowing each other and hating each other late, otherwise many people's sacrifices can be avoided.