Megaloptera are relatively unknown insects across much of their range, due to the adults' short lives, the aquatic larvae's often-high tolerance of pollution (so they are not often encountered by swimmers etc.

These, while formidable in appearance, are relatively harmless to humans and other animals; much like a peacock's feathers, they serve mainly to impress females.

[1] Dobsonfly larvae, commonly called hellgrammites, are often used for angling bait in North America.

The Asian dobsonfly Acanthacorydalis fruhstorferi can have a wingspan of up to 21.6 cm (8.5 in), making it the largest aquatic insect in the world by this measurement.

[3] Adult megalopterans closely resemble the lacewings, except for the presence of a pleated region on their hindwings, helping them to fold over the abdomen.

The larvae are carnivorous, and are known to feed on small invertebrates, such as crustaceans, clams, worms and other insects.

When they reach maturity, the larvae crawl out onto land to pupate in damp soil or under logs.