A peformance artist attends an election rally for Cameroon presidential candidate for the opposition Univers party, Cabral Libii in Yaounde, Cameroon 06 October 2018. Africa's oldest president Paul Biya who has been in power since 1982 is up against eight candidates when voters go to the polls 07 October 2018. 6.9 million registered voters will head to the polls but marginalised anglophone separatists in the North West and South West of the country threaten to disrupt the elections. (Photo by Nic Bothma/EPA/EFE)

A boy covers his head with fallen leaves as he enjoys a stroll with his family in a park in downtown Frankfurt, Germany, November 6, 2016. (Photo by Kai Pfaffenbach/Reuters)

A golden pheasant and squirrels are seen in Lushan County of Pingdingshan City, central China's Henan Province, November 14, 2017. (Photo by Liu Xianguo/Xinhua/Barcroft Images)

A camel is seen as he is being brought for the foot surgery at the Dubai Camel Hospital in Dubai, UAE, December 11, 2017. (Photo by Satish Kumar/Reuters)

Kashmiri children play with snow on a wooden foot bridge in the interiors of Dal Lake in Srinagar on January 16, 2017. A cold wave has further tightened its grip in Jammu and Kashmir, with most places in the state recording sub-zero temperatures. (Photo by Tauseef Mustafa/AFP Photo)

A woman looks at head of bluefin tuna on display in front of a store at Tsukiji fish market in Tokyo, Monday, February 19, 2018. The large bluefin are particularly valuable in Japan, where they are considered a premium sushi and sashimi fish. A single fish sold for more than $1.75 million at an auction in Japan in 2013. (Photo by Koji Sasahara/AP Photo)

A Dead Leaf butterfly (Kallima inachu formosana, also called Orange Oakleaf Butterfly) rests on a tree trunk at the Taipei Zoo in Taipei, Tawian, 03 August 2019. Dead Leaf butterfly can be found in Tropical Asia from India to Japan. When its wings close, it resembles a dead leaf, providing camouflage against predators including birds, ants, spiders and wasps. (Photo by David Chang/EPA/EFE)

In this August 24, 2019 photo, a tractor pulls a trailer that was converted into a swimming pool as it drives along the roads of El Infernal neighborhood in San Andres in the province of Pinar del Río, Cuba. The idea for the mobile tractor-pool was hatched by local parents, to make their kids happy and fight the harsh Caribbean heat. (Photo by Ramon Espinosa/AP Photo)