The tiny (microscopic) eggs can be carried to your mouth by contaminated food, drink or your fingers. Once swallowed, the eggs hatch in the intestines and mature into adult worms within a few weeks. Female pinworms move to the anal area to lay their eggs, which often results in anal itchingAnal itching, also called pruritus ani (proo-RIE-tus A-nie), has several possible causes. They include infections, hemorrhoids and ongoing diarrhea.https://www.mayoclinic.org › symptoms-causes › syc-20369345