Bangladeshi Muslims travel on the roof of an overcrowded train as they head to their hometowns ahead of Eid al-Adha in Dhaka, Bangladesh, Friday, September 1, 2017. The festival commemorates the story of Abraham and his readiness to sacrifice his son as an act of obedience to God, who provided a lamb to be used instead. (Photo by Bernat Armangue/AP Photo)

Kamchatka brown bears at Kurile Lake in Kamchatka peninsula’s volcanic terrain, Russia on August, 2017. Kamchatka brown bears are generally not dangerous to humans, and only 1% of encounters result in attack. (Photo by Igor Ivanko/Anadolu Agency/Getty Images)

A female member of Romania's military adjusts her hat before taking part in the national day military parade in Bucharest, Romania, Friday, December 1, 2017. Thousands of Romanian troops staged a military parade to celebrate Romania's national day, but key politicians didn't attend, signaling tensions between the president and the ruling left-wing coalition over plans to revamp the justice system. (Photo by Vadim Ghirda/AP Photo)

A young visitor interacts with a baby hippopotamus swimming in its enclosure at the Berlin Zoo on January 1, 2018. Tourists and locals flocked to the zoo in the German capital on the unseasonably warm first day of the year. (Photo by Odd Andersen/AFP Photo)

A participant wearing a motorcycle helmet gets sprayed with firecrackers, during the “Beehive Firecrackers” festival at the Yanshui district in Tainan, Taiwan on March 1, 2018. According to Taiwan's Tourism Bureau, the “beehive” festival started in the late 1885 as a request to the gods to spare Yanshui from a cholera outbreak which was making its way through the villages. (Photo by Tyrone Siu/Reuters)

The carcass of a fattened pig, winner of the “holy pig” contest, is attached to a metal frame during a sacrificial ceremony in Sanxia district, in New Taipei City, Taiwan February 1, 2017. The winner of Taiwan's “holy pig” ceremony on Thursday defended the lunar new year tradition against critics who argue the fattened animals are raised under cruel conditions. (Photo by Tyrone Siu/Reuters)

Ender Moreno looks for gold at La Culebra gold mine in El Callao, Bolivar state, southeastern Venezuela on March 1, 2017. Although life in the mines of eastern Venezuela is hard and dangerous, tens of thousands from all over the country head for the mines daily in overcrowded trucks, pushed by the rise in gold prices and by the severe economic crisis affecting the country, aggravated recently by the drop in oil prices. (Photo by Juan Barreto/AFP Photo)

Pilgrims lift up their dresses as they cross the Quema river during the annual El Rocio pilgrimage in Villamanrique, near Sevilla on June 1, 2017. El Rocio pilgrimage is the largest in Spain with hundreds of thousands of devotees wearing traditional outfits converging in a burst of colour as they make their way on horseback and decorated carriages across the Andalusian countryside. (Photo by Cristina Quicler/AFP Photo)