Indian Runner ducks march past farm buildings at the Vergenoegd wine estate near Cape Town, South Africa, May 16, 2016. Each day, a quack squad of killer ducks are released for the first of two sorties at South Africa's Vergenoegd wine farm in Stellenbosch. Their mission – seek and destroy thousands of pests out to ruin the season's harvest. Fanning out across the vineyards, some 1,000 Indian Runner ducks hone in on their hidden targets with uncanny precision, locating the tiny white dune snails feasting on budding vines. (Photo by Mike Hutchings/Reuters)

South Korean college students wearing masks hold up candles as they march after a rally calling for South Korean President Park Geun-hye to step down in Seoul, South Korea, Saturday, November 12, 2016. Hundreds of thousands of people flooded Seoul's streets on Saturday demanding the resignation of Park amid an explosive political scandal, in what may be South Korea's largest protest since it shook off dictatorship three decades ago. (Photo by Lee Jin-man/AP Photo)

In this March 29, 2016 photo, a man shoulders a coffin with the remains of a loved one who was slain more than two decades ago by Shining Path rebels, as he walks to the cemetery for a group burial service, in Ccano, a village in the Huanta area of Ayachcuo department, Peru. Presidential candidate Keiko Fujimori's base of support is in places like Ccano, where promises to build roads, clinics and schools recall her agronomist father’s own legacy of delivering aid to the long-overlooked countryside. (Photo by Rodrigo Abd/AP Photo)

A young man with an amputated leg poses for a photograph standing by his broken artificial limb in the rebel-controlled area of Maaret al-Numan town in Idlib province, Syria March 20, 2016. Two university students forced to interrupt their studies have learnt to make and fit hundreds of new limbs in the past four years in opposition-held areas of Syria. A mobile clinic operating from a truck has gone some way to improve access to treatment. While most patients are between 15 and 45, the clinic also helps children and the elderly with replacement limbs. (Photo by Khalil Ashawi/Reuters)

A museum employee views “Details of Renaissance Paintings (Sandro Botticelli, Birth of Venus, 1482)” by Andy Warhol at the Victoria and Albert museum in London, Britain, March 2, 2016. The piece forms part of “Botticelli Reimagined”, an exhibition exploring the ways artists have responded to the artistic legacy of the fifteenth century artist Sandro Botticelli, and including over fifty artworks by Botticelli himself. (Photo by Toby Melville/Reuters)

A Hindu holy man, or sadhu, smeared with ashes smokes marijuana in a chillum during the Shivaratri festival on the premises of Pashupatinath Temple in Kathmandu, Nepal, March 7, 2016. Hindu holy men from Nepal and India come to this temple to take part in the Maha Shivaratri festival. Celebrated by Hindu devotees all over the world, Shivaratri is dedicated to Lord Shiva, and holy men mark the occasion by praying, smoking marijuana or smearing their bodies with ashes. (Photo by Navesh Chitrakar/Reuters)

A 14 year-old Myanmar girl carries three bags of powdered-limestone to load in to a boat on the bank of Ayeyarwaddy River, on International Women's Day in Mandalay, Myanmar, Tuesday, March 8, 2016. Migrant workers living along Ayeyarwaddy riverbank earn bout 5000 Kyats (US Dollar 4) a day for loading and unloading goods. (Photro by Hkun Lat/AP Photo)

A worker stands under the Airlander 10 hybrid airship during its unveiling in Cardington, Britain March 21, 2016. The world's largest aircraft has been unveiled for the first time since being fully assembled in the UK. The 302ft (92m) long Airlander 10 – part plane, part airship – was floated in a First World War hangar in Bedfordshire. (Photo by Darren Staples/Reuters)