Pill Woodlouse - Armadillidium vulgare


Length: 18 mm. It gets its name from its ability to roll into a tight ball when disturbed. This woodlouse is typically slate grey in colour, but red or patchy forms may arise.

Similar Species

It can be confused with the Pill Millipede but is distinguished by the narrow plates at the tail-end and by having just one pair of legs per segment compared to the two found on the millipede.

The Southern Pill Woodlouse has also been found or rare occasions in Leicestershire. This is of similar size but can be distinguished by the side plates flaring out like a skirt. It also cannot roll into a complete ball, leaving a small gap.

Identification difficulty

Occurs mainly on calcareous soils, except in coastal areas, and is able to withstand much drier conditions than most other woodlice. It shows a distinct preference for chalky or limestone sites with stony turf.

When to see it

All year round.

Life History

Feeds on dead organic matter, which it detects by means of taste and smell. During the breeding season, reproductive females develop a 'brood pouch'. The fertilised eggs pass into this fluid-filled chamber and the young crawl out of the brood pouch when they are fully developed.

UK Status

Common and widespread in Britain, but fewer records from Scotland.

VC55 Status

Common in Leicestershire and Rutland.

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Leicestershire & Rutland Map


Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2020+ | 2015-2019 | pre-2015

UK Map