Pinworm (Threadworm)

Natural Habitat

The human gastrointestinal tract, specifically the large intestine and rectum.

Diet & Feeding

Feeds on intestinal contents and mucosal secretions within the human host.

Behavior Patterns

Adult females migrate out of the anus at night to lay thousands of microscopic eggs on the surrounding skin, causing intense itching. The life cycle continues when eggs are accidentally ingested through contaminated hands, surfaces, or food.

Risks & Benefits

Risks: Causes enterobiasis, characterized by perianal itching, sleep disruption, and irritability. While generally not dangerous, it is highly contagious. Benefits: None to the host; it is an obligate parasite.

Identified on: 2/20/2026