Hookworm larvae hatch in warm, moist soil and grow through 3 larval stages.  Upon entering the third stage (L3), the larva travel to high points, such as the tips of grass blades.  Upon contact with human skin, the larvae penetrate the skin and travel to the blood and into the heart.  From the blood, larvae travel into the lung capillaries and into the lung.  The hookworm larvae then migrate up the trachea to be swallowed into the stomach.  The larvae travel through the digestive tract to the small intestine where they mature into adults, and feed on components of blood.  The adult hookworms create eggs which are released in feces into the environment, to start the cycle all over again.