About Pterostichus madidus (Fabricius, 1775)
Pterostichus madidus, commonly called the black clock beetle, is a species of ground beetle native to Europe. Adult black clock beetles typically reach 14–20mm in length. They are entirely black, though their legs are most often red, reddish brown, or black. This species is most abundant during summer, and breeds in the autumn. It is commonly found in gardens, grasslands, and dry woodland, where it occurs under stones, within grass clumps, or under loose bark. In the United Kingdom, this beetle is often referred to as the rain beetle, because it tends to appear when rain is approaching. An old folk superstition holds that stepping on or killing one of these beetles will cause rain to fall.