Pinworm

Natural Habitat

The human large intestine (specifically the cecum and appendix) and the perianal area during egg-laying.

Diet & Feeding

Content of the human intestine and epithelial cells.

Behavior Patterns

Nocturnal activity; gravid females migrate out of the anus at night to deposit eggs on the skin of the perianal area, causing an itchy sensation (pruritus ani).

Risks & Benefits

Risks include intense itching, sleeplessness, and potential secondary bacterial infections from scratching. They provide no ecosystem benefits and are considered a common human parasite, particularly in children.

Identified on: 3/29/2026