This is thread worm. It causes Strongyloidiasis. Its filariform larvae enter human host from the soil after which they travel through the blood stream to the lungs. They are then passed to the alveoli where they are aspirated to be swallowed into the foodway where they mature into adults and live in the proximal small intestine by burrowing into the mucosa. They release eggs which pass into feces and can continue the cycle or pass into the circulation to reinfect the individual thereby perpetuating the infection cycle within its host. It may also perform its cycle in the soil instead of in man.