Bangladeshi fisherman feed their otters as they catch fish in Narail some 208 kms from Dhaka on March 11, 2014. The fishermen are using a rare technique that relies on coordination between man and trained otters, a centuries-old fishing partnership that has already long died out in other parts of Asia. (Photo by Munir Uz Zaman/AFP Photo)

A remote-controlled plane in the form of a witch flies over a neighborhood as the sun sets during Halloween in Encinitas, California, U.S. October 31, 2016. (Photo by Mike Blake/Reuters)

A boy and a serviceman pose for a picture during Marines Day celebration in the Black Sea port of Sevastopol, Crimea, November 27, 2016. (Photo by Pavel Rebrov/Reuters)

Food affected villagers cross flood waters through a bamboo bridge in the flood affected Morigaon district of Assam state, India, 05 July 2016. Continuous rain since last couple of days inundated six districts of Assam effecting more than 100 thousand people in the second wave of floods in Assam state. (Photo by EPA/Stringer)

2016 Rio Olympics, Weightlifting, Final, Women's 69kg, Riocentro, Pavilion 2, Rio de Janeiro, Brazil on August 10, 2016. Leidy Solis (COL) of Colombia competes. (Photo by Stoyan Nenov/Reuters)

Tourists kissing front of Malaysia's landmark Petronas Twin Towers with lights on before turned off to mark Earth Hour 2016 in Kuala Lumpur, Malaysia, 19 March 2016. Earth Hour takes place worldwide at 8.30 p.m. local time and is a global call to turn off lights for 60 minutes to raise awareness of the danger of global climatic change (Photo by Fazry Ismail/EPA)

A demonstrator is carried during a rally in support of a identity check draft law and against delinquency, in Santiago, Chile April 30, 2016. (Photo by Carlos Vera/Reuters)

Sugar gliders, Candy and Popcorn, enjoy their favourite food, Nectar, at Wild Life Sydney Zoo on February 14, 2017 in Sydney, Australia. The treat made up of honey, high protein baby cereal and egg yolks is the human equivalent to chocolate to the Sugar Gliders. St. Valentine's Day or the Feast of Saint Valentine began as a celebration of the early Christian Saint Valentinus. From the 18th Century onwards it has steadily transformed into a celebration of romantic love and sentiment in many countries around the world. (Photo by James D. Morgan/Getty Images)