A Humboldt penguin swims in a pool during the annual stock take at ZSL London Zoo in London, Thursday, January 2, 2020. Caring for more than 500 different species, ZSL London Zoo's keepers face the challenging task of tallying up every animal large and small, every mammal, bird, reptile, fish and invertebrate at the Zoo. (Photo by Frank Augstein/AP Photo)

The three orangutans at Pairi Daiza zoo, Belgium, developed a “special bond” with the otters after their river was run through the ape enclosure on March 2020. The zoo said it enriched both species’ environments. An animal – and this is even more the case of orangutans, with whom humans share 97 per cent of their DNA – must be entertained, occupied, challenged and kept busy mentally, emotionally and physically at all times. (Photo by Pascale Jones/The Sun)

A military aircraft flies low through the Mach Loop in west-central Wales on September 25, 2025 during Cobra Warrior 25-2, one of Nato’s largest multinational air exercises. The operation, running across the UK until October 3, brings together air forces from the UK, US, Canada, Italy and Germany for three weeks of high-intensity training in challenging low-level environments. (Photo by Tony Marsh)

These horses are pictured in the Khentii province in eastern Mongolia during the Winter Horse Festival – where skillful horsemen gather to challenge the strength of their horses and show off their riding skills. Pictures were taken by Batzaya Choijiljav, a travel company director from Mongolia. Here: The fur of a horse ices up in the –40 cold of Mongolia. (Photo by Batzaya Choijiljav/Caters News)

Fascinated by the texture and color of water artist Elizabeth Patterson challenged herself to recreate the absurdly complex formation of water droplets on rain-streaked windshields. Her ongoing series titled Rainscapes blends drawing, hyperrealism, and traditional landscape techniques resulting in images that can be seen as both real and abstract.

Mariam Emad from Parkour Egypt “PKE” practices her parkour skills around buildings on the outskirts of Cairo, Egypt on July 20, 2018. A group of Egyptian women gather at an abandoned park in a Cairo suburb once a week, climbing walls and jumping around in the strenuous physical discipline known as Parkour, while also challenging the country's conservative social norms. (Photo by Amr Abdallah Dalsh/Reuters)

Men are held by Iraqi national security agents, to be interrogated at a checkpoint, as oil fields burn in Qayara, south of Mosul, Iraq, Saturday, November 5, 2016. Islamic State fighters launch counterattacks in the thin strip of territory Iraqi special forces have recaptured in eastern Mosul, highlighting the challenges ahead as the battle moves into more densely populated neighborhoods where coalition air power must be used more selectively. (Photo by Felipe Dana/AP Photo)

An Indian paramilitary soldier stands guard at a polling station during the second phase of India's general elections, in Srinagar, Indian controlled Kashmir, Thursday, April 18, 2019. Kashmiri separatist leaders who challenge India's sovereignty over the disputed region have called for a boycott of the vote. Most polling stations in Srinagar and Budgam areas of Kashmir looked deserted in the morning with more armed police, paramilitary soldiers and election staff present than voters. (Photo by Dar Yasin/AP Photo)