Threadworms are a kind of parasite that live in the lower intestine (bowel). Female worms lay their eggs around the anus at night or in the early hours of the morning, each laying around 10,000 eggs.
Threadworms look like small, short pieces of white cotton around 5-10 mm in length. Their eggs are so small, they are almost invisible.
Threadworm eggs are so small, ~1,000 eggs can fit on the head of a pin!