A Palestinian boy herds sheep in front of the ruins of Yasser Arafat International Airport, which was bombed by Israel in the past, in Rafah in the southern Gaza Strip February 5, 2016. Nabil Shurafa's travel agency in Gaza was once packed with clients booking flights to London, Paris, New York or cities across the Arab world. These days, he's lucky if anyone comes in, as so few people can get out. (Photo by Ibraheem Abu Mustafa/Reuters)

Yuanlei Liao, the singer of hardcore band called Thank Ray wears a read scarf after performing on the stage of Mao Live House during the club's last public concert night in central Beijing, China April 23, 2016. Mao Live House, a prominent live rock music venue in Beijing, shut its doors on the weekend, the latest closure to hit China's rock music scene. Owner Li Chi said the club, popular among fans of punk, metal and alternative rock since it opened nine years ago, was forced to close due to tighter rules on live performances. (Photo by Damir Sagolj/Reuters)

Model Daisy Lowe has been camouflaged into a wall of daisies by world-leading body paint artist Carolyn Roper, to showcase the Samsung QLED TV's Ambient Mode feature in London, United Kingdom on August 2, 2018. The work took eight hours to complete. (Photo by Matt Alexander/PA Wire)

Bollywood actress and former p*rn star Sunny Leone stands with her wax likeness during its unveiling at the Madame Tussauds museum in New Delhi, India, Tuesday, September 18, 2018. The statue unveiled Tuesday represents the 37-year-old celebrity's acceptance by mainstream Indian society even as conservative Indian politicians condemn her p*rn-star past. (Photo by Anupam Nath/AP Photo)

Central Palo Seco power station of the Puerto Rico Electric Power Authority (PREPA) is seen behind a cemetery, in San Juan, Puerto Rico on January 22, 2018. (Photo by Alvin Baez/Reuters)

A helicopter flies in front of the Wolf Moon as it rises over London, England on January 20, 2019. The Wolf Moon, the Full Moon on January 20-21, 2019, is a Supermoon, making it look bigger and brighter than usual during the total lunar eclipse. (Photo by Dinendra Haria/Rex Features/Shutterstock)

Behaviour: Mammals category. Giant Gathering by Tony Wu, USA. Dozens of sperm whales mingled noisily off Sri Lanka’s northeast coast, stacked as far down as Tony could see. This was a congregation of dozens of social units, like a gathering of the clans. Aggregations like this could be a critical part of the whales’ rich social lives but are rarely reported. Some two thirds of the population was wiped out before commercial whaling was banned in 1986. This kind of major gathering could be “a sign that populations are recovering”, says Tony. (Photo by Tony Wu/Wildlife Photographer of the Year 2017)

Residents recently returning to their area cleared by government troops react as they ride a tricycle a day after President Rodrigo Duterte declared the liberation of Marawi city in southern Philippines Wednesday, October 18, 2017. Sporadic explosions continue Wednesday as Philippine soldiers fought to gain control of the last pocket of Marawi controlled by Islamic militants. (Photo by Bullit Marquez/AP Photo)