Woodlouse (specifically common pill bug or sow bug)

Scientific Name: Armadillidium vulgare

Order & Family: Order: Isopoda; Family: Armadillidiidae

Size: Approximately 8.5 to 18 mm in length.

Woodlouse (specifically common pill bug or sow bug)

Natural Habitat

Damp, dark places such as under rocks, logs, leaf litter, and occasionally indoors in moist areas like basements.

Diet & Feeding

Scavenger that primarily eats decaying organic matter, such as rotting wood, leaves, and fungi.

Behavior Patterns

Nocturnal; they are known for their ability to roll into a tight ball (conglobation) when threatened to protect their soft underside. They are terrestrial crustaceans that require moisture to breathe through gill-like structures.

Risks & Benefits

Harmless to humans as they do not bite or sting. They are beneficial to the ecosystem as decomposers, helping to recycle nutrients back into the soil, but can be considered a minor nuisance if found indoors.

Identified on: 6/28/2026