Pinworm, also called threadworm, is the common name for Enterobius vermicularis, a small intestinal parasite that infects millions of children worldwide. The adult worms live in the colon, and females migrate at night to lay eggs around the anus, causing the intense itching that is the infection’s hallmark. Transmission is faecal-oral via contaminated hands, bedding, and food, and the eggs survive in the environment for weeks, making household spread rapid. Though more a hygiene than a foodborne problem, contaminated produce and poor handwashing before eating contribute. Treatment is simple, with anthelmintic drugs like mebendazole, but the whole household is treated simultaneously and bedding washed hot to break the cycle. Good handwashing and short fingernails remain the lasting prevention.