Rough Woodlouse

Common Rough Woodlouse (Porcellio scaber)

When I reached the top of the stairs in the house the other day, I found this little fellow trundling across the carpet—a long way from any of the "damp corners" that these tiny crustaceans typically prefer. It's a Common Rough Woodlouse, a relative of the lobsters and shrimps of the sea and the second woodlouse species for the property. After scooping it up for a few photos, I put it out into our very damp garden, where it will hopefully thrive. When I examined it closely, it was easy to see that it was quite different from the Common Pill Woodlouse we found in October. For one thing, it has a flanged "skirt" all around the edges of its body. And it can't roll itself into a tight armoured ball. It's covered with rough little nubbins on its plates, and has larger eyes than the Common Pill Woodlouse does. Plus it has two spiky uropods sticking out the back. Woodlice use those uropods to help shed water (eg. raindrops) from their bodies; they hold the two uropods together and press them repeatedly against the ground until all of the water has drained off. This is one of the most common species of woodlouse in England and Wales—and the species most likely to enter houses. It is found in a wide variety of habitats, including some which are slightly drier than those preferred by other woodlouse species (including upstairs carpets, perhaps?). Like all of Britain's woodlice, it's primarily a vegetarian. Surprisingly, these small creatures can live two or three years, so maybe we'll be seeing our visitor again some day.