A donkey carrying sacks of coal walks through the narrow tunnels of a coal mine, in Choa Saidan Shah in Punjab province April 29, 2014. Coal miners in Chao Saidan Shah use donkeys to transport coal from the depths of the mines to the surface. (Photo by Sara Farid/Reuters)

“The Last Pollen Spore Preparing to Leave a Ladybug Trying to Hold On, Because It Didn't Want to Be Alone”. Photo by Hiep Nguyen Hoang (Hanoi, Vietnam). Photographed in Hanoi, Vietnam, April 2012.

A model presents a hairstyle during the 7th international festival of hairdressing art, fashion and design called “Crystal Angel” in Kiev, Ukraine, on April 18, 2013. (Photo by Gleb Garanich/Reuters)

A schoolgirl collects rubbish from Karachi's Clifton beach early morning April 22, 2013, during a cleaning campaign as part of the commemoration of Earth Day. (Photo by Akhtar Soomro/Reuters)

“Erwin Olaf is a Dutch photographer. Olaf is most famous for his commercial and personal work. His work has received many awards and he has held exhibitions around the world”. – Wikipedia. Photo: «Berlin» Project. Porträt 01, April, 22, 2012. (Photo by Erwin Olaf/Hasted Kraeutler Gallery)

Festival goers run toward the main stage to catch the beginning of Kendrick Lamar's set during the first weekend of Coachella 2012, on April 13, 2012. (AP Photo/Chris Pizzello)

Farmers plant rice seedlings in a paddy in Karanganyar, near Solo, Central Java, Indonesia in this April 13, 2016 photo taken by Antara Foto. (Photo by Maulana Surya/Reuters/Antara Foto)

People dressed as Hungarian Hussars fire a cannon during re-enactment of the battle against Austrian soldiers of the Habsburg dynasty in Tapiobicske, Hungary April 4, 2016. (Photo by Laszlo Balogh/Reuters)