Woodlouse (specifically the Common Woodlouse or Sowbug)

Scientific Name: Oniscus asellus

Order & Family: Order Isopoda, Family Oniscidae

Size: 10 to 18 millimeters (0.4 to 0.7 inches) in length

Woodlouse (specifically the Common Woodlouse or Sowbug)

Natural Habitat

Damp, dark environments such as under logs, rocks, leaf litter, and in basements or crawl spaces.

Diet & Feeding

Detritivorous; they primarily eat decaying plant matter, rotting wood, and fungi, acting as natural recyclers.

Behavior Patterns

They are nocturnal and active at night to avoid desiccation. They are terrestrial crustaceans that breathe through gill-like structures, requiring moisture to survive. They often congregate in large groups to conserve water.

Risks & Benefits

They pose no risk to humans as they do not bite, sting, or spread disease. They are highly beneficial to ecosystems as decomposers that help return nutrients to the soil.

Identified on: 3/7/2026