Pinworm (Human Threadworm)
Scientific Name: Enterobius vermicularis
Order & Family: Order: Oxyurida, Family: Oxyuridae
Size: Females: 8-13 mm long; Males: 2-5 mm long (very thin, thread-like appearance).
Natural Habitat
The human large intestine and rectum; eggs are commonly found on skin, clothing, and household dust.
Diet & Feeding
Feeds on the contents of the human colon and intestinal microbes.
Behavior Patterns
Nocturnal migration; adult females migrate out of the anus at night to deposit thousands of eggs on the perianal skin, which causes intense itching.
Risks & Benefits
Risk: Causes enterobiasis (pinworm infection), characterized by anal itching and restless sleep. Benefit: None to humans; purely a parasitic organism.
Identified on: 2/17/2026