Dicrocoelium dendriticum is a bile duct fluke of ruminants such as sheep, goats and deer as well as pigs. It is often referred to as the lancet fluke because of its blade-like form. It stands apart from most trematodes since it has a land-based life cycle. The definitive host's feces contain contain miracidia which do not hatch until after they are eaten by the first intermediate host, a land snail, such as Cionella lubrica in the U. S. and other species elsewhere. The miracidium emerges inside the intestine of the snail and metamorphoses into a sporocyst in the digestive gland. Daughter sporocysts are produced within the mother sporocyst and in turn produce xiphidiocercaria which are characterized by having a stylet inside the mouth and tails, normal features of aquatic cercaria, despite the fact they terrestrial. After around 90 days post-infection, cercarial production fills the mantle cavity known as the lung of these air-breathing snails. The cercaria irritate the delicate tissues of the lung, resulting in the defensive production of mucous by the snail. The infestation of the lung, causes the snail to cough, expelling mucous, laden with cercaria into its slime trail. As the slime dries, the exterior hardens, protecting the cercaria from dessication. The second intermediate host is the common brown ant, Formica fusca in North America. The ants gather the slime balls containing cercaria and feed it to their developing larvae. Metacercaria develop in the hemocoel of the ant and are infective to any definitive host which may accidentally ingest ants while grazing. One or two of the encysted metacercaria encyst in the subesophageal ganglion, one portion of the ant brain, and there, remarkably alter the ant's behavior, increasing its chances of being eaten by the definitive host. Ants normally retreat to their burrows as the day cools in the late afternoon to evening and remain there till mid-day when the surface of the soil warms. However, infected ants climb to the ends of blades of grass, clinging by their mandibles, during periods of cool when their hivemates have retreated to their burrows. The consequences of this antithetical behavior is that the ant becomes a prime target of accidental predation by the grazer. Upon ingestion by the definitive host, the metacercaria excyst in the duodenum and migrate up the common bile duct to the liver. The adult fluke matures in 6-7 weeks, producing egg capsules about a month later.