Hookworms have developed many adaptations that help them not only survive, but become more efficient parasites.

-The eggs of the hookworm have developed a thin shell that serves as protection. This shell allows them to not be harmed as they travel through and out of the digestive tract.
Hookworm egg- DPDx CDC

-The hookworm larva have an adaptation that allow them to located their host while living in the substrate. They have what are called amphids; these are large paired sensilla on each side of their mouth. These detect the host and allow the hookworms to find, attach, and penetrate the host, in this case, humans.

-The juvenile and adult forms also have adaptations to help them survive. They have developed two pairs of sharp teeth to allow them to attach to the intestines of the host and eat the intestinal mucus. These teeth also allow them to penetrate blood vessels so they can feast on the blood. Along with the thookworm mouth w/ teeth- Wikimedia Commonseeth, the hookworms have a natural anticoagulant secretion that keeps the blood from clotting and allows them to eat longer. Hookworms also possess a hydrostatic skeleton which allow them to more easily move through the substrate and the hosts circulatory and digestive system.