A fan waves a Brazilian flag before the arrival of the Olympic torch ahead of the Rio 2016 Olympic Games on August 2, 2016 in Sao Goncalo, Rio de Janeiro state, Brazil. The torch will arrive in the city of Rio tomorrow and the Games commence on August 5. (Photo by Mario Tama/Getty Images)

Opossums on their mothers back at a game reserve in Central Minnesota, USA, on September 2, 2013. (Photo by Caters News Agency)

Eurocopter's X³ high-speed hybrid helicopter demonstrator performs, September 6, 2010. The Eurocopter X³ (X-Cubed) is an experimental high-speed compound helicopter developed by Eurocopter (now Airbus Helicopters). A technology demonstration platform for Eurocopter “high-speed, long-range hybrid helicopter” or H³ concept, the X³ achieved 255 knots in level flight on 7 June 2013, setting an unofficial speed record for a helicopter. (Photo by Reuters/HO/Eurocopter/Penna)

A dog walks past a handmade replica of Lamborghini Diablo outside a garage rented by Wang Yu and Li Lintao on the outskirts of Beijing, August 21, 2014. Chinese race car enthusiasts Wang Yu and Li Lintao, both in their 30s, have finished designing and making two replicas of the Lamborghini Diablo, which can reach the top speed of 310km/h, and are currently working on a replica of the T-Rex motorcycle. They spent approximately 5 million yuan (around USD 811,899) to buy parts and hire workers, and about 6 years to assemble them with the knowledge they gained from studying mechanology for nearly a decade abroad. Wang and Li went popular after showing their first handmade replica of Lamborghini Diablo at the Beijing International Automobile Exhibition in 2012, and sold their second Lamborghini replica to Alibaba as a collection. (Photo by Petar Kujundzic/Reuters)

Beautiful woman and man playing domination games in bed. (Photo by nd3000/Getty Images)

Girls of University of Cincinnati Stage Grecian Games on April 29, 1921. Garbed in costumes of ancient Greece, fair students of the University of Cincinnati, Ohio arranged a set of Grecian Games for the benefit of the University athletic fund. All of the girl students of the University, who take a great interest in outdoor games and athletics, took part in the games. The fund was greatly increased through the staging of the unique attraction and the girls purpose to give a return engagement. The accompanying photographs show the girl contestants in their Grecian costumes. Photo shows the start of the 100 yard dash. (Photo by Bettmann Archive/Getty Images)

Woman and man playing domination games in bed. (Photo by NDAB Creativity/Rex Features/Shutterstock)

A competitor prepares to snorkle during the World Bog Snorkelling Championships on August 28, 2011 in Llanwrtyd Wells, Wales. In 2012, following the Olympic Games, Llanwrtyd Wells will host the inaugural World Alternative Games. (Photo by Harry Engels/Getty Images)