Trichoniscus is a genus of woodlice. It contains over 100 species, including the common pygmy woodlouse, Trichoniscus pusillus:

Trichoniscus pusillus, sometimes called the common pygmy woodlouse, is one of the five most common species of woodlice in the British Isles. It is acknowledged to be the most abundant terrestrial isopod in Britain. It is found commonly across Europe north of the Alps, and has been introduced to Madeira, the Azores and North America.