Southern Pill Woodlouse Armadillidium depressum

This large British pill woodlouse defies the classic pill bug shape with its distinctly "splayed" appearance—instead of curling into a neat sphere, it flattens and spreads when threatened, adopting a completely different defense posture than its cousins. Relatively common across Britain, you might find it in damp garden beds, under logs, or in compost heaps where moisture never runs dry. The unusual flattened shape appears even when the creature isn't under threat—it's simply built differently. Scientists consider this visual distinction significant enough to warrant its own species classification, separate from the more compact pill woodlice. This splayed posture may actually provide advantages in tight spaces, allowing it to squeeze into crevices where rounder species cannot follow.