Southern Pill Woodlouse

Armadillidium depressum · Order: Isopoda · Family: Armadillidiidae

No source yet on danger. We have no source yet on whether it bites, stings or damages anything.

The Southern Pill Woodlouse can grow up to about 20 mm long, a bit larger than the common woodlouse.

How to recognize it

When it rolls into a ball, a small gap remains instead of a perfect seal. Its rear body (pleon) curves outward, giving it a splayed look.

Adults may reach a length of about 20 mm, slightly longer than the 18 mm of the common woodlouse.

It feeds on dead plant matter.

It can be seen throughout the year.

It is present all year long.

Most records are from southwest Britain near the English Channel, with smaller populations scattered across England.

It looks very similar to the common woodlouse, dark grey to black, but can be told apart by the gap when rolled up.

How can I tell the Southern Pill Woodlouse apart from the common woodlouse?

Look for a small gap when it rolls into a ball and a outward-curving pleon that gives a splayed appearance.

What does it eat?

It feeds on dead plant material.

Is it present all year?

Yes, it can be seen throughout the year.

Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia

Text written 2026-10-23 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-22.