S20 · Insect
Slater (Woodlouse)
Porcellio scaber / Armadillidium vulgare
Harmless crustaceans that roll into a ball. A sign of dampness and decaying organic matter.
- Size
- 8–18 mm
- Habitat
- Damp soil, compost, under rocks and timber
- Activity
- Year-round, nocturnal
Overview
Slaters are actually crustaceans — relatives of crabs and prawns — not insects. They breathe through gills and need moisture to survive, so seeing them indoors means there's a damp problem. They eat decaying plant matter and are beneficial in compost. They don't damage timber, clothing or food.
How to identify
- Oval, segmented body with 14 legs — grey, brown or mottled
- Some species roll into a perfect ball when disturbed (pill bugs)
- Found in damp bathrooms, laundries, under pots and in compost
- Move slowly and prefer to stay hidden in dark crevices
Pro Tip
Slaters are nature's moisture meter. If you see them inside, find and fix the damp problem first.
General guidance only. Information on Home Pest Defence is provided for educational purposes and is not a substitute for professional advice. For termites, venomous spider bites, wasp nests in walls, or protected wildlife, contact a licensed pest controller, your GP, or the relevant state wildlife authority. In emergencies call 000; for poisoning call 13 11 26.