Pinworm

Human large intestine and anal area; eggs can survive on clothing, bedding, and household surfaces

Gastrointestinal contents and cellular debris within the host intestine

Adult females migrate to the anus at night to deposit eggs in the perianal skin folds, causing itching. Life cycle includes ingestion of eggs, hatching in the small intestine, and maturation in the colon.

Risk: Causes Enterobiasis, characterized by intense anal itching and potential secondary bacterial infections from scratching. No ecological benefits.