Liver flukes are a group of about fifteen different species of parasites that share a number of characteristics during their life cycle and result in a similar etiology when they infect humans. In particular, although they can be in several places in the body during the parasite's life cycle, the adults are localized in the liver and surrounding ducts of the animal they infect..They all feed on blood from the host. The adults release eggs which pass through the bile duct to the intestine, where they are excreted. When the eggs are eaten by another host, they infect that host as well.