Woodlice, odd little creatures. They are Crustaceans, which is mainly a marine group (crabs, lobsters, shrimps etc), not Centipedes (arthropods). Their order is Isopoda which comes from the Greek for same feet – they have 14 legs.
They are ancient. The earliest records are from the Eocene period, (50 million years ago), but they may have been around from the Mesozoic period, (around 160 million years ago), which would make sense of the already widespread distribution in place when the fossils began to be found. The Mesozoic period was the golden age of reptiles, divided into 3 eras, 160 million years ago is in the Jurassic period. A Diplodocus (154 to 150 million years ago) could have watched a woodlouse walk across the ground.
Porcellio scaber – common rough woodlouse, 6.4.2014
They live avoiding drying out. They have an exoskeleton, like a suit of armour. It has to be shed at intervals as they grow, and the new one in place underneath is pumped up by the woodlouse to be bigger then the last one. This leaves them with a temporary soft outside, making them vulnerable for a while. They live under things where they are sheltered – so do some of the animals that eat them (some spiders). Birds also hunt them, as do shrews and foxes.
Abney Fungi 