An African giant pouched rat sniffs for traces of landmine explosives at APOPO's training facility in Morogoro on June 17, 2016. APOPO trains the rats to detect both tuberculosis and landmines at its facility. Every year landmines kill or maim thousands of people worldwide. The trained rats sniff for explosive and so are able to detect the presence of landmines far faster than conventional methods which involve metal detection. (Photo by Carl De Souza/AFP Photo)
Inger Utke, left, takes a selfie with Edwin Galarza, dressed as a “Star Wars” themed dinosaur, during Preview Night at Comic-Con International held at the San Diego Convention Center, Wednesday, July 20, 2016, in San Diego. (Photo by Denis Poroy/Invision/AP Photo)
A tourist poses on the glass-bottom bridge at Zhangjiajie Grand Canyon on August 20, 2016 in Zhangjiajie, Hunan Province of China. The Zhangjiajie Grand Canyon's glass-bottomed bridge welcame its trial operation on Saturday and about 8,000 tourists crowded to view the grand glass bridge. (Photo by VCG/VCG via Getty Images)
A worker walks through a salt pan on the eve of May Day or Labour Day on the outskirts of the southern Indian city of Chennai April 30, 2014. India is the third largest salt producing country in the world after China and U.S. with global annual production about 230 million tonnes, according to government data. (Photo by Reuters/Babu)
An athlete pulls a 15-tonne truck during a Truck-Pull event marking the upcoming Independence Day in the Belarus capital Minsk, on July 3, 2014. The former Soviet nation celebrates its Independence Day on July 3 in memory of the end of Belarus occupation by Nazi Germany troops during the Red Army main summer offensive in 1944. (Photo by Sergei Gapon/AFP Photo)