This July 2014 image provided by the Bureau of Land Management shows the interior of the Natural Trap Cave in north-central Wyoming. The cave holds the remains of tens of thousands of animals, including many now-extinct species, from the late Pleistocene period tens of thousands of years ago. Scientists have resumed digging for the first time in more than 30 years. (Photo by AP Photo/Bureau of Land Management)

Demonstrators clash with riot police during a protest against President Sebastian Piñera on October 21, 2019 in Santiago, Chile. President Sebastian Piñera suspended the 3.5% subway fare hike and declared the state of emergency for the first time since the return of democracy in 1990. Protests had begun on Friday and developed into looting and arson, generating chaos in Santiago, Valparaiso and a dozen other cities resulting in at least 8 dead. (Photo by Marcelo Hernandez/Getty Images)

A Mapuche Indian child waves a Mapuche people flag during a protest march by Mapuche Indian activists against Columbus Day in downtown Santiago, Chile, October 12, 2015. (Photo by Ivan Alvarado/Reuters)

Internally displaced Syrian children stand at the entrance of their makeshift shelter that is an underground cave in Om al-Seer, southern Idlib countryside, Syria December 26, 2015. (Photo by Khalil Ashawi/Reuters)

A couple of monkeys look from inside their cage at a rescue and rehabilitation center in Santiago, Chile, Saturday, November 22, 2014. Elba Munoz who runs the center, says that one of the goals of the Center for the Rescue and Rehabilitation of Primates is to stop the trafficking of the animals. (Photo by Luis Hidalgo/AP Photo)

Dancers perform during the Sambodromo do Brasil jungle party in the Cave stage, Elrow Town at Queen Elizabeth Olympic Park on August 18, 2018 in London, England. (Photo by Ollie Millington/Redferns)

Hindu pilgrims walk along a mountain path as they make their pilgrimage to the sacred Amarnath Cave, one of the most revered Hindu shrines, near Baltal, Kashmir, India. (Photo by Daniel Berehulak)

A demonstrator uses a slingshot during a protest against Chile's government in Santiago, Chile, November 14, 2019. (Photo by Jorge Silva/Reuters)