Which of the following is not a characteristic of pinworms?

Pinworms, also known as Enterobius vermicularis, are indeed a prevalent parasitic infection, particularly among children. One of the main characteristics of pinworms is that their eggs can be easily transmitted from person to person through contaminated surfaces or via touch, particularly after scratching the itchy area around the anus. This leads to the rapid spread of the infection in settings like schools or daycare facilities.

Pinworms are known for causing significant discomfort primarily due to the itching they cause around the anal region, particularly at night when the female pinworms lay their eggs. This intense itching is often one of the first signs of an infection.

While pinworms are a significant health concern and common in children, they are relatively small and not typically visible to the naked eye. They can be about 1 cm long, which means they do not appear large when compared to other types of parasitic worms. The size of pinworms is one of the distinguishing characteristics that make the answer regarding their visibility the correct choice, as it highlights a common misconception that they are larger and more noticeable than they actually are.