Although dormant volcanoes are usually quiet, “zombie volcanoes” like Bolivia’s Uturuncu display a surviving amount of activity for a volcano that hasn’t erupted in 250,000 years. Although technically not dead, dormant volcanoes usually show little activity unless they’re on the inevitable road to eruption. However, some volcanoes defy this easy categorization, and chief among them is the long-dormant Uturuncu volcano in Bolivia. Meaning “jaguar” in the indigenous language Quechua, Uturuncu hasn’t erupted for 250,000 years—give or take 5,000 years or so. Understanding these signs of activity could help scientists sort through which volcanoes are an impending threat and which are simply blowing smoke.