People dressed as zombies take part in a “Zombie Walk” parade in Athens, Greece, February 25, 2017. (Photo by Michalis Karagiannis/Reuters)

Myanmar's military parade to mark the 72nd Armed Forces Day in the capital Naypyitaw, Myanmar March 27, 2017. (Photo by Soe Zeya Tun/Reuters)

A woman already appears to be regretting her choice of heels for the day out during the Grand National Festival at Aintree Racecourse on April 8, 2017 in Liverpool, England. (Photo by Alamy Stock Photos)

Women look on as Sauber's German driver Pascal Wehrlein steers his car during the second practice session at the Monaco street circuit on May 25, 2017 in Monaco, three days ahead of the Monaco Formula 1 Grand Prix. (Photo by Andrej Isakovic/AFP Photo)

Hostesses pose in front of a Suzuki Ignis car at the European Motor Show in Brussels, Belgium, January 13, 2017. (Photo by Francois Lenoir/Reuters)

In this photo taken Wednesday, December 5, 2018, a woman who scavenges recyclable materials from garbage for a living is seen through a cloud of smoke from burning trash, surrounded by Marabou storks who feed on the garbage, at the dump in the Dandora slum of Nairobi, Kenya. As the world meets again to tackle the growing threat of climate change, how the continent tackles the growing solid waste produced by its more than 1.2 billion residents, many of them eager consumers in growing economies, is a major question in the fight against climate change. (Photo by Ben Curtis/AP Photo)

An undated handout picture released on January 10, 2017 by the Issekinicho publishing house shows an inter- species sexual behaviour between a male Japanese macaque and female sika deer, in Yakushima Scientists revealed on January 10, 2017 the “highly unusual” behaviour of a male monkey filmed trying to have sеx with female deer in Japan – a rare case of inter- species nookie. (Photo by Editions Issekinicho/AFP Photo)

“Himalayan Dog”. This dog just appeared out of nowhere and followed us for an entire week during our trekking trip in the Himalayan outback. He always used to sleep in front of our tent and guarded us in the nights. When I decided to get up at 4 a.m. to climb the next 5000 m peak for sunrise he accompanied me as well. On the top he was sitting for the entire 30 minutes on this place looking straight into the countryside. Photo location: Ladakh, India. (Photo and caption by Sebastian Wahlhuetter/National Geographic Photo Contest)