This bat gives a cheeky smile as he gobbles down his food at Singapore Zoo, on September 10, 2013. (Photo by Benny Iskander/HotSpot Media)

An Indian Sikh Nihang, or warrior, performs Gatka martial arts skills during a procession at the Golden Temple in Amritsar on January 6, 2014, as part of birth anniversary celebrations of Guru Gobind Singh. The birth anniversary of Guru Gobind Singh, the tenth Sikh guru, is marked on January 6. (Photo by Narinder Nanu/AFP Photo)

An Iraqi man comforts his 4-year-old son at a regroupment center for POWs of the 101st Airborne Division near An Najaf, Iraq, March 31, 2003. The man was seized in An Najaf with his son and the U.S. military did not want to separate them. (Photo by Jean-Marc Bouju/Associated Press)

A child plays with a soap bubble on the city hall plaza on March 14, 2015 in Paris. (Photo by Dominique Faget/AFP Photo)

A cloud of black smoke billows out the exhaust pipe of John Robertson's diesel dragster as he runs down the track during the 2015 NHRA Kansas Nationals, Friday, May 22, 2015, at Heartland Park in Topeka, Kan. (Photo by Chris Neal/The Topeka Capital-Journal via AP Photo)

U.S. President Donald Trump boards Air Force One to depart for Vietnam from Beijing Airport in Beijing, China on November 10, 2017. (Photo by Jonathan Ernst/Reuters)

Cockpit of a SCG 0003S racecar is seen during the 87th International Motor Show at Palexpo in Geneva, Switzerland March 8, 2017. (Photo by Arnd Wiegmann/Reuters)

The space shuttle Atlantis lifts off from launch pad 39A at the Kennedy Space Center in Cape Canaveral, Florida May 14, 2010. (Photo by Pierre Ducharme/Reuters)