Pinworm

Natural Habitat

The lower gastrointestinal tract (cecum and colon) of humans, who are the only natural hosts.

Diet & Feeding

Intestinal contents and epithelial cells of the human host.

Behavior Patterns

Adult females migrate out of the anus at night to deposit eggs on the perianal skin, causing intense itching. Eggs become infectious within 4-6 hours.

Risks & Benefits

Risks include enterobiasis (pinworm infection), anal itching, and potential secondary bacterial infections from scratching. They provide no known benefits to the host.

Identified on: 6/2/2026