The wood louse is not an insect, but a crustacean. It is the only crustacean adapted to life on earth; that’s why it is always found in moist areas. Indeed, its shell is a hard exoskeleton composed of chitin, limestone and calcium phosphate. Its color varies between dark grey and pale brown. It can live up to four years and reach its sexual maturity at around 3 months. It ranges in size from 12 to 15 mm when adult and has 7 pairs of legs. The wood louse is very useful for the ecosystem, since it feeds on rotten organic matter. Outside, it is found under rocks and logs, under piles of leaves, in other words, anywhere humidity levels are high. It can invade our buildings through cracks in the foundation as well as through badly-caulked windows and doors. It can easily survive in our homes where humidity is high such as in bathrooms and basements.