A boy sleeps in a hammock while his mother works at a brick kiln on the outskirts of Yangon February 1, 2015. (Photo by Soe Zeya Tun/Reuters)

A child sleeps under a table at the Jorkpan market in Sinkor district in Monrovia, Liberia on May 2, 2016. (Photo by Marco Longari/AFP Photo)

Singer-songwriter Sheryl Crow meets Clyde the Sea Lion, the star of SeaWorld San Diego's “Sea Lion Tonite”, at the marine-life park's Sea Lion and Otter Stadium on August 3, 2011 in San Diego, California. Crow and her sons spent the day a SeaWorld meeting, feeding and learning about sea turtles, penguins and sea lions, other park animal ambassadors. Crow was performing in San Diego on her summer concert tour with Kid Rock. (Photo by Mike Aguilera/SeaWorld San Diego via Getty Images)

Workers sleep on a railway track under repair in New Delhi, India, June 15, 2018. (Photo by Saumya Khandelwal/Reuters)

A man sleeps at Beirut's Corniche, a seaside promenade, in Lebanon May 2, 2016. (Photo by Alia Haju/Reuters)

Sleeping Anthidium. Female Anthidium punctatum; Size: 7 mm. (Photo by John Hallmén)

Cambodian children sleep on a pavement at a park in Phnom Penh on July 8, 2016. (Photo by Tang Chhin Sothy/AFP Photo)