The sensation of worms wriggling in the anus is not related to trichomonas, but is mainly due to pinworms. Trichomonas is a common cause of vaginitis and lives mainly in the vaginal area, which causes changes in the vaginal environment. Trichomonas lives a relatively simple life and has only trophozoites and does not form encysts. Trichomonas cannot be seen with the naked eye and can only be observed through a microscope. During the disease, the patient does not feel the worms crawling around. The anal canal is usually free of trichomonads because the environment is alkaline. When there is a sensation of worms crawling in the anal canal, it is mostly caused by pinworms. Pinworms are mainly parasitic in the human intestine and crawl out of the anus to lay eggs outside the anus during the egg-laying period. This causes itching and dampness in the anal area, and some people may even have the sensation of worms moving around.