Painted Woodlouse Porcellio spinicornis
The Painted Woodlouse measures 9 to 14 mm. It always has a black head. The animal in the picture is a rather dull one, for this species is usually more colourful. The spots may be brown or yellow, the basic colour is variable as well: some animals are even completely pink. It is similar to the Common Shiny Woodlouse, but slimmer. Experts tell the two species apart by looking at some details: the Painted Woodlouse has two flagella segments and two pairs of pleopodal lungs. The Common Shiny Woodlouse has three flagella segments and no pleopodal lungs. The lungs are white spots situated at the last segments of the body. To see them, you have to turn the animal around, for they are sitting on the underside of the animal. The flagellum is the last part of the antenna.
The Painted Woodlouse loves humans. Actually it can be found in or near human dwellings exclusively. Old walls, roofs and attics, but also cemetaries are good places to live in. It tolerates much drier conditions than most other woodlice. Where the Common Rough Woodlouse is usually found only in cellars and other damp places, the Painted Woodlouse may be found in dry places like attics. It is regularly seen indoors just walking about. Still this being a nocturnal animal mainly, not everyone will be aware of its presence in their house. In winter they hide in cavity walls or under roof tiles and are rarely seen.
This species is scarce to common on the continent. In Britain it is considered a common species.