Bison along the Bitterroot Valley's Eastside Highway north of Stevensville, Montana, are covered in snow following a blizzard on November 23, 2010. (Photo by Perry Backus/The Missoulian)

A member of the German wireless police picks up signals on the radio equipment he carries on his back, while his colleague takes notes. (Photo by General Photographic Agency/Getty Images). Circa 1925

A workman takes a siesta on a girder during the building of Radio City, the city of New York spread out below. (Photo by General Photographic Agency/Getty Images). Circa 1933

A young man “painting” the Eiffel Tower. (Photo by Keystone/Getty Images). 9th May 1970

A Humboldt penguin stands on weighing scales whilst being photographed by members of the press during a photocall at the annual weigh-in at London Zoo in London, Britain, 24 August 2016. Every animal that is in the zoo is weighed and measured and the statistics recorded so the data can be shared with zoos across the world. (Photo by Hannah McKay/EPA)

A groom leads his horse in the equine pool after working out on the track, during early morning workouts for the upcoming Derby race in Mumbai January 29, 2015. (Photo by Danish Siddiqui/Reuters)

Residents with faces covered in ash ride on a motorcycle as Mount Sinabung volcano erupts, in Sukandebi village in Karo Regency, Indonesia's North Sumatra province, Indonesia June 13, 2015, in this photo taken by Antara Foto. (Photo by Rony Muharrman/Reuters/Antara Foto)

A hungry tiger was almost left with a ROARing headache – after nearly colliding into a pane of glass as it dived underwater for a slab of meat. (Photo by Caters News)