Adult "D. viviparus" worms reside in the bronchial tree of the animal's lungs. They lay eggs into the airways (bronchi). These eggs are coughed up and subsequently swallowed by the host. The eggs hatch into Stage 1 larvae (L1) in the gastrointestinal tract of the ruminant host. These L1 larvae are shed in the feces or manure. In the feces, larvae mature through two stages and become infective as L3 stage larvae. Cattle feces supports the growth of "Pilobolus" sp. fungi. The L3 larvae of "D. viviparus" invade the inside of these fungi, and wait in the fungal sporangium. When the fungus sporulates, the larvae are dispersed as much as 10 feet in a pasture.