An adult chimp plays with a young chimp at Chimp Haven in Keithville, La., Monday, February 18, 2013. One hundred and eleven chimpanzees will be coming from a south Louisiana laboratory to Chimp Haven, the national sanctuary for chimpanzees retired from federal research. (AP Photo/Gerald Herbert)

Young women sit at a doorway during the annual San Antonio Abad (Saint Anton Abbott) festival in Trigueros, southwest Spain January 25, 2015. Thousands of people arrived in Trigueros to participate in this annual catching of food and presents, part of a traditional three-day religious festival. (Photo by Marcelo del Pozo/Reuters)

A young Hindu girl sits for a ceremony where she and other girls are worshipped as “Kumari”, or living goddess, during Ram Navami festival, at a temple in Kolkata, India, Saturday, March 28, 2015. Ram Navami marks the birth of Hindu God Rama. (Photo by Bikas Das/AP Photo)

Young people fight for fun with their pillows, during the International Pillow Fight Day at the Place des Grottes, in Geneva, Switzerland, Saturday, April 4, 2015. The annual International Pillow Fight Day takes place in hundreds of cities around the world. (Photo by Salvatore Di Nolfi/AP Photo/Keystone)

A young woman dressed as a zombie takes part in a zombie parade as part of the Brussels International Fantastic Film Festival 2014 in Brussels, Belgium, 12 April 2014. More than a hundred of participants took to the streets of Brussels. (Photo by Ulien Warnand/EPA)

Men slide in the mud during the Boryeong Mud Festival at Daecheon Beach in Boryeong, South Korea, Saturday, July 22, 2017. The 20th annual mud festival features mud wrestling and mud sliding. (Photo by Ahn Young-joon/AP Photo)

(L-R) Young Paris, Lionel Richie, Isabela Moner and Austin Butler attend the Jeremy Scott Fashion Show during New York Fashion Week at Spring Studios on September 8, 2017 in New York City. (Photo by Ben Gabbe/Getty Images)

For the Torajan people of Indonesia, death is part of a spiritual journey: families keep the mummified remains of their deceased relatives in their homes for years – and traditionally invite them to join for lunch on a daily basis – before they are eventually buried. Here: Todeng died in 2009. A young relative of his, Sam, lights him a cigarette and changes his glasses. (Photo by Claudio Sieber Photography/The Guardian)