Thaumetopoeidae

Thaumetopoeidae (sometimes incorrectly spelled "Thaumatopoeidae") is a small family of moths in the order Lepidoptera. The genera in this family have been historically treated as a subfamily within Notodontidae instead.

The larval stage of some Thaumetopoeidae are known as processionary caterpillars, so named because they move in columns in search of food, resembling a procession. Some of the species, like the Pine and Oak Processionary, can constitute a health hazard.