Common Woodlouse

Common Woodlouse ©

Common woodlouse

Scientific name: Oniscus asellus
The grey and armoured common woodlouse is familiar to most of us as the minibeast often found under rocks and in compost heaps in the garden. It is an important recycler of nutrients, feeding on decaying matter.

Species information


Length: 1.4cm

Conservation status


When to see

January to December


The common woodlouse feeds on dead and decaying matter and is an important nutrient-recycler in the wide variety of habitats it lives in. It can be very numerous in compost heaps or under rocks in the garden. It easily becomes desiccated, so will hide in damp places during the day, especially in hot, dry weather. There are about 30 species of woodlouse in the UK, which range from pink to brown to grey in colour.

How to identify

The common woodlouse has smooth, shiny, grey 'armour' (an exoskeleton made up of segments or 'plates') with yellow patches and lighter grey edges.



Did you know?

Woodlice are actually terrestrial crustaceans, not insects, so are more closely related to crabs and shrimps.

How people can help

Our gardens are a vital resource for wildlife, providing corridors of green space between open countryside, allowing species to move about. In fact, the UK's gardens provide more space for nature than all the National Nature Reserves put together. So why not try planting native plants and trees to entice birds, mammals and invertebrates into your backyard? To find out more about encouraging wildlife into your garden, visit our Wild About Gardens website: a joint initiative with the RHS, there's plenty of facts and tips to get you started.