Quick facts

Common name(s): pill woodlouse, roly poly

Scientific name: Armadillidium vulgare

Family: Armadillidiidae

Habitat: woodland, grassland, urban areas

Predators: birds and small mammals

Origin: native

What do pill woodlice look like?

Adults: can grow up to 18mm long and are usually slate grey. Their exoskeletons have several segments, or plates. The pill woodlouse is more rounded than the common woodlouse.

Young: look like a smaller, white versions of adults and are carried in a pouch under the mother’s abdomen.

What do pill woodlice eat?

Pill woodlice feed on dead plant matter, as well as lichen and algae. They find food using their senses of taste and smell.

Male and female pill woodlice on exposed bark

Credit: Custom Life Science Images / Alamy Stock Photo

How do pill woodlice breed?

Females develop a brood pouch during the breeding season. When fertilised, the eggs pass into it and hatch, developing in the pouch until the young are ready to emerge.

Where to find pill woodlice

The pill woodlouse is common and widespread throughout the UK, but is more frequent in the south and east.

Signs and spotting tips

You can spot pill woodlice throughout the year, though they may be less active in cold weather. Look for them on the soggy ground under stumps of wood or plant pots.

Did you know?

In the US, children sometimes keep pill woodlice, or pill bugs as they are known there, as pets.

Threats and conservation

This species is common and not believed to be under threat.