A robot Ecce by the Robot studio is pictured at the world's largest industrial technology fair, the Hannover Messe, in Hanover April 13, 2015. (Photo by Wolfgang Rattay/Reuters)

A woman walks inside a building in downtown Havana, Cuba April 21, 2016. (Photo by Alexandre Meneghini/Reuters)

Lightning streaks across the sky as lava flows from a volcano in Eyjafjallajokul April 17, 2010. (Photo by Lucas Jackson/Reuters)

Pawel Karpinski and Nadine Kinczel of Poland dance as they compete during IPC Wheelchair Dance Sport European Championships in Lomianki near Warsaw, November 9, 2014. (Photo by Kacper Pempel/Reuters)

Masked Guggen music bands parade through the streets on the occasion of the beginning of the Fasnacht Carnival of Lucerne, Switzerland, early 23 February 2017. (Photo by Urs Flueeler/EPA)

A boy jumps into a pool of mud during the traditional “Bloco da Lama” or “Mud Street” carnival party, in Paraty, Brazil, Saturday, February 25, 2017. Legend has it the “bloco” was born in 1986 after local teens hiking in a nearby mangrove forest smeared themselves with mud to discourage mosquitoes and then wandered through Paraty. The party grew year after year, but revelers eventually were banned from parading in the colonial downtown after shopkeepers complained pristine white walls were stained with the hard-to-remove mud. (Photo by Mauro Pimentel/AP Photo)

A mouse rides on the back of a frog in floodwaters in the northern Indian city Lucknow June 30, 2006. (Photo by Pawan Kumar/Reuters)

Wild elephants, including a tusker (C), rummage through garbage dumped at an open ground in the village of Digampathana in north- central Sri Lanka on August 19, 2017. Sri Lanka has banned the dumping of garbage at open fields and near wildlife reserves, but the practice continues. (Photo by Lakruwan Wanniarachchi/AFP Photo)