Thaumetopoeidae

Thaumetopoeidae 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 etymology of the family name is the ancient greek θαυματόεις, marvelous, and ποιέω, to do, and literally means showing beautiful things. This explains why the name is sometimes spelled Thaumatopoeidae, incorrectly from the taxonomic standpoint, but in accordance with etymology.

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 processionaries, can constitute a health hazard.