Pilobolus crystallinus is a very unusual fungus found on animal dung. In an attempt to get it’s spores away from the dung and onto grass it has evolved a mechanism to project them many centimeters away. In nature, the stalks are very phototropic and aim towards the sun to maximize the distance the spores travel from their position on the dung pile. Once on the grass, an herbivore may graze upon them and begin the life cycle again. This is an 18-hour time-lapse movie of Pilobolus crystallinus, also known as the "dung cannon" or "hat thrower". Images were taken at 2-minute intervals for the first 2/3s of the movie and then switched to 1-minute intervals for the final third. Medium is an agar “poo-cube” seeded with spores collected on the lid of deep Petri dish. On the two higher resolution versions of this, you can see moisture develop on the stalks and is then possibly absorbed by the fungus as the vesicle swells to pop off the spore packet.