You may have pinworms if you experience itching around the anus, especially at night. This itching happens because female pinworms lay eggs around the anal area during the night. Other symptoms can include vaginal itching in girls, trouble sleeping, irritability, teeth grinding, occasional stomach pain, or bedwetting. Sometimes tiny white threadlike worms can be seen around the anus, in underwear, or in the toilet after a bowel movement. However, pinworm infections can sometimes cause no symptoms at all. To confirm if you have pinworms, a common method is the "tape test." This involves pressing the sticky side of a piece of clear tape against the skin around the anus first thing in the morning before bathing. The tape may pick up pinworm eggs, which a healthcare provider can then examine under a microscope. The test might need to be done on several consecutive days to improve accuracy. Another way to check is by shining a flashlight on the anal area at night to look for the small white worms. If you have persistent anal itching or suspect you have pinworms, it's advisable to see a healthcare professional for diagnosis and treatment.