Aka Pill Bug, House Crustacean With a Shell

Word Meaning:

WOODLOUSE — Any of the terrestrial isopod crustaceans of the suborder Oniscidea, which have a rigid, segmented exoskeleton, often being capable of rolling into a ball, and feed only on dead plant matter, usually living in damp, dark places, such as under stones or bark.

Definitions from Wiktionary.