Women perform a pole dancing routine during the national day celebration of “Urban Pole” dance along a street in Monterrey, Mexico, on June 9, 2013. (Photo by Daniel Becerril/Reuters)

A Chinese couple take pictures in an interactive installation art work named “You and Me” on Valentine's Day at 798 Art Zone on February 14, 2012 in Beijing, China. (Photo by Feng Li/Getty Images)

A walruses at Hagenbeck Zoo in Hamburg, Germany on July, 7, 2015. (Photo by Werner Struss/Startraks action)

A baby elephant eats in a swamp in Amboseli national park, Kenya, March 19, 2017. (Photo by Goran Tomasevic/Reuters)

Undated David Yarrow handout photo of a gorilla as the self-taught wildlife photographer promotes his book, Encounter. (Photo by David Yarrow/Clearview/PA Wire)

A thirsty timber wolf, Lithuania, 2018. (Photo by Erikas Plucas/Alamy Stock Photo)

A chicken gingerly crosses the double yellow line of a country road near Roseburg in western Oregon, USA on July 16, 2018. (Photo by Robin Loznak/ZUMA Wire/Alamy Live News)

A zookeeper feeds a hippopotamus with a watermelon in its enclosure in Belgrade's zoo, Serbia, July 20, 2015. Temperatures in Serbia have risen up to 40 degrees Celsius (104 degrees Fahrenheit), according to official meteorological data. (Photo by Marko Djurica/Reuters)