In one to four weeks, the eggs hatch into nymphs and these mature in the water. Before becoming an adult, nymphs molt ten to fifteen times to allow room for growth. As a nymph and an adult, dragonflies fall prey to fish, amphibians and birds. In addition, nymphs have become a popular type of bait used by fishermen and in some areas, particularly in the United States, the fish bait market has significantly affected dragonfly populations. As predators, adult dragonflies feed on flying insects, such as mosquitoes which they catch on their wings, either by flying around or sitting stationary.
Dragonflies are unique in that they are carnivorous, eating other insects in abundance.
In several areas of the world, this has proven to be an effective method of ensuring the balance of biodiversity, while also keeping mosquito populations in check, and that is a very good thing.