True, most parasites will move through the body and pooped out then, be picked up by other animals or bugs and transferred to a new host through, being digested or injected, rinse and repeat and spread. Aka, wash them hands and dont eat poop. Oo. Grew up with horses, it was kinda common to hear of kids getting pinworms w/horses because, they were inhaling the eggs that were scraped off the animals during worm season. "horse flies".