A panoramic survey of the ruminants, from giraffes to deer to cattle to antelopes to goats and sheep. We divvy the ungulates into groups based on the number of toes they have, and ask them directly, “why do you chew your cud?” And hey, what is “cud”? We look at how the cud-chewers differ from their grazing, herbivorous cousins, and how a four-chambered stomach can turn a green lawn into a hearty meal.