Threadworms live for about 5-6 weeks in the gut and then die. Before they die, the female worms lay tiny eggs around the back passage (anus).

Where do Threadworms lay their eggs?

Threadworms lay their eggs around an infected person's anus (bottom), usually at night. Along with the eggs, the worm also secretes a mucus that causes itching. If the eggs get stuck on the person's fingertips when they scratch, they can be transferred to their mouth or on to surfaces and clothes.

How do you kill Threadworm eggs?

To remove threadworm eggs and prevent re-infection: Change and wash underwear, nightwear and, if possible bed linen and towels, every day for a few days. A hot water wash, or the heat of an iron, will kill the eggs.