People in Kathmandu joke that the face mask has now become part of the national dress – an indispensable accessory in an effort to protect themselves from the dust. Nepal has the worst air quality in the world, according to the Environmental Performance Index. (Photo by Pete Pattisson/The Guardian)

A girl yawns as she and others wait for the start of their first day in school, an occasion known as the Day of Knowledge, in the small town Ignalina, some 110km (68 miles) north of the capital Vilnius, Lithuania, Monday, September 2, 2019. (Photo by Mindaugas Kulbis/AP Photo)

Public Space series, 2015. This series by Morteza Niknahad and Behnam Zakeri tends toward cinema, taking an almost cartoonish view of modern life in Iran. This work was inspired by the social life of dolphins. (Photo by Morteza Niknahad and Behnam Zakeri/The Guardian)

Miniscule larvae carve winding tunnels as they eat through small leaves in a small forest near the town of Velbert in western Germany in July 2022. The hungry green sawfly larvae measure just three millimetres in length and are difficult to spot on the leaves of the beech tree unless up close. (Photo by Christian Brockes/Solent News)

Participants take part in the 14th annual “No Trousers Tube Ride” event on the London Underground on January 12, 2025. The event, staged by Improv Everywhere, takes place every January in New York City and has since expanded internationally. What began as a small prank with just seven participants has grown into a global celebration of silliness, with dozens of cities, including London, joining in each year. (Photo by Guy Bell/Alamy Live News)

An aerial view shows boats sailing in the marshes of Chibayish in Iraq's southern Dhi Qar province on February 8, 2025. (Photo by Asaad Niazi/AFP Photo)

A young tiger tries to get at poultry parts hidden in a pumpkin at Magdeburg Zoo, Germany on October 30, 2025. The zoo is celebrating Halloween from October 31, 2025 to November 1, 2025. In addition to the puppet theater, children's carousel and children's train, visitors can carve their own pumpkins, which are then distributed to the zoo animals and serve as food. (Photo by Klaus-Dietmar Gabbert/Avalon)

Athletes from Australia's Olympic team going to the 2016 Olympics in Rio present their uniforms alongside Brazilian Samba dancer Sashya Jay at an official unveiling ceremony at Sydney's Bondi Beach, March 30, 2016. (Photo by Jason Reed/Reuters)