Internally displaced Syrians who fled Raqqa tie ropes for their tents in a camp in Manbij, Syria on April 6, 2017. (Photo by Rodi Said/Reuters)

A vendor sleeps at his vegetables shop at a main market in Colombo, Sri Lanka May 31, 2016. (Photo by Dinuka Liyanawatte/Reuters)

Annual celebration of Dinagyang festival of Iloilo, Philippines. (Photo by Raniel Jose Castañeda/Sony World Photography Awards)

Grumpy Cat in Las Vegas, America on August 5, 2014. Grumpy Cat aka Tardar Sauce has died on May 14, 2019 at home in Arizona at the age of seven due to complications from a urinary tract infection. Her family's statement said: “Besides being our baby and a cherished member of the family, Grumpy Cat has helped millions of people smile all around the world – even when times were tough. Her spirit will continue to live on through her fans everywhere. Grumpy's Family – Tabatha, Bryan and Chyrstal”. (Photo by Mediapunch/Shutterstock)

These breathtaking images capture the hidden depths of one of the worlds largest caves, which is so big its home to a beach, a river and a jungle. At more than 130m high, and 150m across, the imposing cave is so big as high as the London Eye and wider than one-and-a-half football pitches. Here: The campers set up inside the cave on the beach. (Photo by Lars Krux/Caters News)

“Double head vulture”. On the day of windy days during raptors migration some people in my country start to catch these tired raptors, so in this day we go to photograph some raptors and we saw these tow tired vultures, so we start to drag them away from the hunters until they reach a good hidden place, to make them safe until they start a new journey. Photo location: Kuwait. (Photo and caption by Mohd Khorshed/National Geographic Photo Contest)

In this Tuesday, March 12, 2019 photo, a visitor takes part in an immersive experience showing visitors how dogs see from inside the head of a dog at the California Science Center in Los Angeles. A new exhibit at a Los Angeles museum examines the relationship between dogs and humans and explores why the two species seem to think so much alike and get along so well. “Dogs! A Science Tail” opens Saturday, March 16, 2019, at the California Science Center. (Photo by Richard Vogel/AP Photo)