Turkana tribesmen walk with guns to protect their cattle from rival tribes near Baragoy, Kenya August 4, 2017. (Photo by Goran Tomasevic/Reuters)

Balinese man watches Mount Agung volcano almost covered with clouds as he stands at a temple in Karangasem, Bali, Indonesia, Tuesday, September 26, 2017. An increasing frequency of tremors from the volcano indicates magma is continuing to move toward the surface and an eruption is possible, a disaster agency official said Tuesday. Tourists are cutting short their stay to the island, where an eruption would force the airport to close and strand thousands. (Photo by Firdia Lisnawati/AP Photo)

Spectators pass through security screening ahead of the New Year's Eve celebration in Times Square in New York, on Sunday, December 31, 2017. (Photo by Peter Morgan/AP Photo)

In this January 3, 2018 photo several female Gelada baboons, also known as bleeding-heart baboons, cuddle with their youngs in order to keep warm at the Wilhelma zoo in Stuttgart, Germany. (Photo by Sebastian Gollnow/DPA via AP Photo)

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)

Brazil's synchronised swimmers Luisa Borges (front) and Maria Eduarda Miccuci perform during a training session at the Rio Olympic Park in Rio de Janeiro, Brazil, April 7, 2016. (Photo by Pilar Olivares/Reuters)

Belarussian rhythmic gymnast Melitina Staniouta takes a selfie as she has her make-up done in Minsk, May 29, 2016. Photos show her training and competing, as well as trying on her official Olympic uniform and getting ready for a photo shoot. (Photo by Vasily Fedosenko/Reuters)

Cloud inversion taken at Sunrise in Mam Tor, Derbyshire, UK on August 30, 2016. (Photo by David Zdanowicz/REX Shutterstock)