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)

A hippopotamus performs during a show at the circus in Krasnoyarsk, Siberia, Russia, July 7, 2016. (Photo by Ilya Naymushin/Reuters)

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

2016 Rio Olympics, Gymnastics training, Rio Olympic Arena, Rio de Janeiro, Brazil on August 4, 2016. Close up of the feet of Rebecca Downie (GBR) of United Kingdom as she trains on the beam. (Photo by Dylan Martinez/Reuters)

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 woman in a USA sash, who would help show U.S. President Barack Obama to his seat, waits with other women in traditional dress for the start of the ASEAN Summit gala dinner in Vientiane, Laos September 7, 2016. (Photo by Jonathan Ernst/Reuters)

Comic Con fans in costume arrive for the 2nd day of the 2016 New York Comic Con at the Jacob Javits Center on October 7, 2016. The four- day event which runs October 6-9 is the largest pop culture event on the East Coast. (Photo by Timothy A. Clary/AFP Photo)

Sunrise over a moor viewed from Littaford Tor, Dartmoor, UK, 2016. Autumn visits the windswept moors and granite tors of Dartmoor earlier than the rest of the south-west. While there aren’t many trees here, autumn shades appear in golden ferns and tan heather. Littaford Tors, near Two Bridges and a mile from Princetown, is a short walk and can be combined with a visit to the adjacent Wistman’s Wood. (Photo by Stuart Holmes)