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)

This picture taken on May 31, 2018 shows a villager walking between abandoned houses covered with overgrown vegetation in Houtouwan on Shengshan island, China' s eastern Zhejiang province. Houtouwan was a thriving fishing community of sturdy brick homes that climb up the steeply hilled island of Shenghshan, but is now abandoned, with entire houses completely overgrown as if vacuum- sealed in a lush layer of green. (Photo by Johannes Eisele/AFP 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)

Dead leaf or almost by Guilhem Duvot. Taken in Nován Stráž, Slovakia. Describe what is pictured? A dead leaf grasshopper. How does this image fit with the theme of the competition? The perfect camouflage – nature is amazing. I saw the grasshopper only because it jumped. (Photo by Guilhem Duvot/Royal Society of Biology)

Graduates dance as they take part in a “Last school bell” ceremony at a school in Minsk, Belarus on May 30, 2018. (Photo by Vasily Fedosenko/Reuters)

Split-view of a killer whale at sunrise off the coast of Northern Norway. At least half of the world’s killer whale populations are doomed to extinction due to pollution of the oceans, a new study says. (Photo by Audun Rikardsen/Science)

Communist supporters hold portraits of Soviet leader Josef Stalin as they queue to lay flowers at the grave of Stalin to mark the 139th anniversary of his birth, in Moscow's Red Square, Russia, Friday, December 21, 2018. (Photo by Pavel Golovkin/AP Photo)

Old Heidelberg, Dog with Pipe, 1905. (Photo by Detroit Publishing Company)