There are around 500 species and nine families in this order. The insects in this order are found throughout the world. They are most common in humid temperate and subtropical environments. There are around 68 species in five families found in North America.

The name mecoptera comes form the great word "meco" which means long and "ptera" which means wing. Scorpionflies and hangingflies have long forewings and hindwings that are the same length. They are omnivores and eat insects, rotting plants, pollen, and nectar. They have a chewing mouth part and a beak.

Males in the Panorpidae family of scorpionflies have a long, scorpion-like tail that curves up over their abdomen. The tail is really their reproductive organ.