Nanopsocetae

Louse (: lice) is the common name for any member of the infraorder Phthiraptera, which contains nearly 5,000 species of wingless parasitic insects. Phthiraptera was previously recognized as an order, until a 2021 genetic study determined that they are a highly modified lineage of the order Psocodea, whose members are commonly known as booklice, barklice or barkflies.

Liposcelididae (historically often referred to as "Liposcelidae") is a family of booklice of the order Psocodea (formerly Psocoptera), belonging to the suborder Troctomorpha. Members of this family are small and flattened, and often wingless. Mesothorax and metathorax fused in wingless forms.

Pachytroctidae is a family of thick barklice in the order Psocodea (formerly Psocoptera). There are about 15 genera and at least 90 described species in Pachytroctidae.

Sphaeropsocidae is a family of Psocodea (formerly Psocoptera), belonging to the suborder Troctomorpha. Females of this family have reduced, beetle-like elytra, and lack hindwings, with males have either small or absent wings. The family comprises 22 known species (four of them fossils) in eight genera.