The Common Pill-Bug (Armadillidium vulgare), sometimes also called Potato Bug or Common Pill Woodlouse, is a widespread European species of woodlouse.
The Common Pill-Bug may reach a length of 18 mm, and is capable of rolling into a ball when disturbed.
Its body is usually dark gray, sometimes with irregularly arranged yellowish spots.
The Common Pill-Bug is able to withstand drier conditions than many other woodlouse species, and is restricted to calcareous soils or coastal areas.
It can be distinguished from the similar looking Armadillidium nasatum and Armadillidium depressum by the gap that A. nasatum and A. depressum leave when rolling into a ball; A. vulgare does not leave such a gap.

On the balcony of our friends' apartment in Ferragudo.

Ferragudo, Algarve, Portugal, 2 June 2023