Turkana tribesmen walk with guns in order to protect their cattle from rival Pokot and Sambur tribesmen near Baragoy, Kenya February 14, 2017. Cattle rustling and competition for grazing have long troubled northern Kenya, but severe drought and political rivalries ahead of the elections have exacerbated the situation between ethnic tribes. (Photo by Goran Tomasevic/Reuters)

Pablo Holcer tests out a VR system made by Neurable that allows the user to control with their thoughts as the EEG headset interprets thoughts into actions in the VR environment at SIGGRAPH 2017 in Los Angeles, California, July 31, 2017. (Photo by Mike Blake/Reuters)

A fan cosplays as Aloy from Horizon Zero Dawn during the 2017 New York Comic Con, Day 4 on October 8, 2017 in New York City. (Photo by Roy Rochlin/WireImage)

Britain's Queen Elizabeth, second left, sits next to fashion editor Anna Wintour, third left, and Caroline Rush, chief executive of the British Fashion Council (BFC) as they view Richard Quinn's runway show before presenting him with the inaugural Queen Elizabeth II Award for British Design, as she visits London Fashion Week's BFC Show Space in central London, Tuesday, February 20, 2018. (Photo by Yui Mok/Pool photo via AP Photo)

Journalists walk through the corridor of the stopped third reactor at the Chernobyl nuclear power plant in Chernobyl, Ukraine April 20, 2018. (Photo by Gleb Garanich/Reuters)

Rihanna and Drake perform at the BRIT Awards at the O2 arena in London, Britain, February 24, 2016. (Photo by Stefan Wermuth/Reuters)

Devil Ark manager Dean Reid reacts as Tasmanian Devil joeys climb on him before the first shipment of healthy and genetically diverse devils to the island state of Tasmania leave the Devil Ark sanctuary in Barrington Tops on Australia's mainland, November 17, 2015. The largest group so far of disease-free Tasmanian devils has been released in the wild, as part of plans to save the carnivorous marsupials from a cancer threatening them with extinction. (Photo by Jason Reed/Reuters)

Pakistani street performers sit around fire waiting for customers on a chilly evening in Rawalpindi, Pakistan, Wednesday, November 11, 2015. Some parts of Pakistan are facing a harsh winter. (Photo by B. K. Bangash/AP Photo)