Participants run through the streets of the Back Bay during the 16th annual Santa Speedo Run in Boston, Massachusetts, December 12, 2015. (Photo by Brian Snyder/Reuters)

Labourers load a three-wheeled vehicle onto the back of a van at the Mercato market in Addis Ababa October 9, 2015. Addis Ababa's “Mercato” – Italian for “market” – is reputedly the biggest open-air market in Africa, lying in the west of the capital. (Photo by Tiksa Negeri/Reuters)

Men hang at the back of a truck loaded with farm produce along a road in Ikeja district in the commercial capital Lagos, Nigeria December 19, 2016. (Photo by Akintunde Akinleye/Reuters)

A model gets final adjustments back stage before participating in a plus size fashion show in Nairobi, Kenya, October 7, 2017. (Photo by Baz Ratner/Reuters)

A dog wearing ski goggles rides on the back of a man as they both stand in Times Square in New York, USA on January 25, 2021. (Photo by John Angelillo/UPI/Rex Features/Shutterstock)

A group of PETA supporters protest Canada Goose's use of coyote fur, with “Canada Goose Kills” painted on their backs in New York, USA on October 18, 2018. (Photo by Erik Pendzich/Rex Features/Shutterstock)

A great crested grebe feeds a chick sitting on its mother’s back on a lake in Cáceres, Spain. (Photo by Jose Luis Ruiz/Solent News & Photo Agency)

A group of daredevil divers get perilously close to a school of deadly sharks – and one even lies on his back with his arm folded. The relaxed diver swims on his back and almost hugs the shark who is floating directly above him. The freedivers – Carlos Estrabeau, 28, and 29-year-old Ocean Ramsey – are friends with photographer Raul Boesel Jr. Photographer Raul Boesel Jr from Curitiba, Brazil, travelled to West End in the Bahamas to capture images of the giant sharks. (Photo by Raul Boesel/Solent News & Photo Agency)