But it’s an intriguing example of how earthworms can help humans. As they move through the soil, earthworms loosen and mix it up, helping to aerate and drain it. This brings nutrients to the surface, making the soil more fertile, and helps prevent flooding and erosion.

aortic arches

When the earthworm swallows small particles of soil and bits of dead plants and animals, muscles push the food to a chamber or sac called a crop. The crop stores food for a short time.

Pinworms can usually be treated completely with two doses of over-the-counter medicine called pyrantel pamoate, available in the United States under the brand names Pin-X and Reese’s Pinworm Medicine. Take one dose immediately and another dose two weeks later.

Threadworms usually produce no symptoms except an itchy bottom. In fact, people may harbour them for years without realising it.

Children can get threadworms when they accidentally get worm eggs on their hands and swallow them. This might happen if they come into contact with people with worms or with worm-infected dust, toys or bed linen.

Threadworms look like thin, white, cotton threads. Sometimes you can see them in faeces (stools or motions) in the toilet.

However, hygiene measures alone may work. The worms die after about six weeks. Provided that you do not swallow any new eggs, no new worms will grow to replace them. So, if you continue the hygiene measures described above for six weeks, this should break the cycle of re-infection, and clear your gut of threadworms.

A grown pinworm is yellowish white, slender and about one centimetre long. Around four weeks after ingestion, the adult female moves down the gut and exits the body via the anus to lay a batch of eggs on the surrounding skin, often at night. The worm then dies, her reproductive mission complete.

Mebendazole is the main medication used to treat threadworm infections. It can be bought over the counter from your local pharmacy or prescribed by your GP. It’s available as a chewable tablet or a liquid. Mebendazole works by preventing the threadworms absorbing sugar, which means they should die within a few days.