The eggs are laid in or near water; there are a few species that are an exception to this rule. The hatchlings develop through a series of stages, or instars. At the end of each stage they molt and form a larger more developed version of themselves. The size of the prey depends usually on the size of the larvae or the stage of development it is at. Because they are aquatic, the larvae differ noticeably from the adults, both in structure and in behavior. Wing sheaths are not even apparent in the first few stages. They usually develop halfway through the larvae stage.

Larvae development ranges between 3 to 8 weeks. It will molt approximately 8 to 17 times, and grow up to 5 cm in length. During the last stage the larva will stop eating, as its organs are being transformed into those of an adult.