Title photo by Distinctly Average

Woodlice are crustaceans, and get their name from being found in wood, and 'louse' (a parasitic insect) however, they are neither insects or parasites!

There are over 3500 species of woodlouse, and are found throughout the world except Antarctica

Above photo by Nico Ardans

Their ubiquity has resulted in many (up to 250) different local names for them including...

• Boat-builder (Newfoundland, Canada)
• Butcher boy or butchy boy (Australia, mostly around Melbourne)
• Carpenter or cafner (Newfoundland and Labrador, Canada)
• Cheeselog (Reading, England)
• Cheesy bobs (Guildford, England)
• Cheesy bug (North West Kent, Gravesend, England)
• Chiggy pig (Devon, England)
• Chisel pig
• Chucky pig (Devon, Gloucestershire, Herefordshire, England)
• Doodlebug (also used for the larva of an antlion and for the cockchafer)
• Gramersow (Cornwall, United Kingdom)
• Hog-louse
• Millipedus
• Mochyn coed ('tree pig'), pryf lludw ('ash bug'), granny grey in Wales
• Pill bug (usually applied only to the genus Armadillidium)
• Potato bug
• Roll up bug
• Roly-poly
• Slater (Scotland, Ulster, New Zealand and Australia)
• Sow bug
• Woodbunter
• Wood bug (British Columbia, Canada)
• Wood pig (mochyn coed, Welsh)
  source

Above photo by mark faux

They have dark grey or black shells, with armour like exoskeletons made of 7 plates. Each plate has 2 pairs one pair of legs attached, making 14 legs in total. They grow between 0.7mm to 18mm, and can live up to 2-3 years!

Above photo by davholla2002

Their main defensive behaviour is to roll up into a ball, and they can also release an odourous chemical to deter predators. They will also 'ball up' in order to prevent dehydration, and moisture loss during dry periods!

Above photo by Jim McLean

They are living fossils! Their aquatic ancestors lived in the oceans during the Silurian and Devonian periods. Later on, probably during the Carboniferous, they had evolved to live on land

Above photo by Sam

During this aquatic to terrestrial transition they had to evolve a brood pouch (marsupium) to prevent their eggs and young from drying out (Their ancestors would have released eggs directly into the water).

Above photo by Brian Valentine

Another adaptation is breathing via their gills which are located on their hind legs and are always covered with a thin layer of water. As a result they have to live in moist, damp environments. They also prefer to live in groups!

Image source

They eat decaying leaves, fungus, mold, and even the droppings of other animals. They help to break down vegetation and organic matter and play an important role in the nutrient cycle!

Above photo by Siew Chuan Cheah

They need to shed their exoskeleton as they grow, and this molt takes place in two stages. Firstly, the back half is lost, then about 2-3 days later, the front half sheds. Most other athropods shed their cuticles in one go

Above photo by Max Thompson

Woodlice can tolerate contaminated soil, unlike most other creatures!

....they can crystallise heavy metal ions midgut like copper, zinc, cadmium, arsenic and lead. This cleans up soil and purifies contaminated water. source

Aren't they fab?

Above photo by David Graham

All information from wikipedia here and here unless stated otherwise

As always, I'm not an expert, I just like sharing fun things....also this is my first post with my new mander account....woooo!

edit- 'one pair of legs'