Pinworm

Natural Habitat

The human gastrointestinal tract, specifically the large intestine and rectum; eggs are often found on bedding, clothing, and skin.

Diet & Feeding

They feed on intestinal contents and mucosal cells within the human host.

Behavior Patterns

Female worms migrate out of the anus at night to deposit thousands of eggs on the perianal skin, causing intense itching. The life cycle is completed when eggs are accidentally ingested.

Risks & Benefits

Risk: Causes Enterobiasis, characterized by perianal itching, irritability, and sleeplessness. It is highly contagious among household members. Benefit: None to the host; they are obligate parasites.

Identified on: 2/13/2026