Revellers celebrate during the “Bloco da Lama”, a mud carnival, in Paraty, Brazil, on February 10, 2018. “Bloco da Lama” started in 1986 by teenagers playing with mud and became a traditional event at the historical city of Paraty. (Photo by Mauro Pimentel/AFP Photo)

Tibetan students play at a class break at the Xiangnong primary school on April 15, 2005 in Kangding County of Ganzi Tibetan Autonomous Prefecture, Sichuan Province, southwest China. There is only one teahcer in the Tagong Village, 12 Tibetan students get free education from him in Xiangnong primary school. (Photo by China Photos/Getty Images)

Musicians from the Academy of Contemporary Music play using instruments made of car parts during a photocall on April 16, 2008 in London, England. Ford's unique orchestra made up entirely of Ford Focus car parts. (Photo by Daniel Berehulak/Getty Images)

Tourists look at other festival-goers playing in the mud during the Boryeong Mud Festival at Daecheon beach in Boryeong, about 190 km (118 miles) southwest of Seoul, July 19, 2013. About 2 to 3 million domestic and international tourists visit the beach during the annual mud festival, according to the festival organisers. (Photo by Lee Jae-Won/Reuters)

Damai, 3 years old Bornean orang utan plays courtyard at Surabaya Zoo as he prepares to be released into the wild on May 19, 2014 in Surabaya, Indonesia. The two baby orangutans, brothers, were found in Kutai National Park in a critical condition having been abandoned by their mother on May 14, 2014. The Centre for Orangutan Protection (COP) have since been nursing the animals back to health, treating them for malnourishment and 16 wounds predominantly to the feet and hands. (Photo by Robertus Pudyanto/Getty Images)

Customers drink a coffee as several cats roam at Cat Cafe Melbourne on July 25, 2014 in Melbourne, Australia. Cat Cafe Melbourne is Australias first cat cafe. The cafe has several cats from rescue shelters which live at the premises. Patrons can watch and play with the cats while enjoying a coffee. Cat Cafes are becoming known world wide, the first opening in Taiwan in 1998. (Photo by Scott Barbour/Getty Images)