Ligidium hypnorum is a species of woodlouse found across Europe and western Asia.

[1] It is a fast-moving, active species that rarely grows longer than 9 mm (0.35 in).

[2] It is dark and shiny, and is similar in appearance to the common species Philoscia muscorum, and also the rarer Oritoniscus flavus.

[2] In Great Britain, it was first discovered at Copthorne Common, Surrey, in 1873, and most later records are also from South East England.

These cases have since been reinterpreted, not as distinct taxonomic entities, but as historical findings of individuals infected with IIV-31.