Intestinal worms, (such as threadworms and pinworms) are parasites, and usually live in the small intestine, where they mate and live.

Different Types of Worms

there are worms that live in side the body and outside the body some worms are good for us and others very bad

Threadworms/Pinworms

Threadworms (or pinworms) live in the small intestine and migrate to the anal area during the evening hours. These worms usually do not cause pain, yet they can be extremely itchy. The female worms lay their eggs during the night, which is the cause of the itchiness. They can be removed with a prescription medicine available in pharmacies. The worms should pass through the anus after the medicine is correctly taken.

Hookworms

Hookworms also live in the small intestine of their host, which can be either a cat, dog, or human. These worms suck blood voraciously. However, the blood loss in the stools is occult blood loss (not visibly apparent). These worms are significantly more threatening than pinworms, yet they infect a supposed 800 million people worldwide.

Most other intestinal worms take on dogs and cats as hosts.