Pinworm

Scientific Name: Enterobius vermicularis

Order & Family: Order: Oxyurida, Family: Oxyuridae

Size: Females: 8–13 mm long; Males: 2–5 mm long. (The specimen pictured appears to be a female based on size).

Pinworm

Natural Habitat

The human large intestine (colon and rectum); eggs are found on perianal skin and contaminated environmental surfaces.

Diet & Feeding

Content of the human intestinal tract and potentially mucosal cells.

Behavior Patterns

At night, gravid females migrate out of the anus to deposit thousands of eggs on the surrounding skin before dying. This causes intense itching (pruritus ani). Infection occurs via ingestion of eggs.

Risks & Benefits

Risks: Causes enterobiasis, characterized by itching, disturbed sleep, and irritability. While generally not dangerous, it is highly contagious among household members. There are no known ecological benefits.

Identified on: 2/17/2026