A makeshift cart with containers is seen at a suspected drug tunnel under construction during a media tour by Mexican Army in Tijuana April 7, 2015. Mexican soldiers foiled the construction of a suspected drug tunnel underneath a house near the U.S. border, arresting nine people and impounding a truck used to clear debris, the Army said on Tuesday. Wired with lights, the tunnel was being built next to the Tijuana border crossing, south of San Diego, California, and near a Mexican air force installation as well as a regional federal police facility. (Photo by Reuters/Stringer)

Students from St Andrew's University indulge in a tradition of covering themselves with foam to honour the “academic family” on October 20, 2014, in St Andrews, Scotland. Every November the “raisin weekend” which is held in the university's Lower College Lawn, is celebrated and a gift of raisins (now foam) is traditionally given by first year students to their elders as a thank you for their guidance and in exchange they receive a receipt in Latin. (Photo by Jeff J. Mitchell/Getty Images)

A paramilitary police officer (right) turns around as hostesses line up for roll call ahead of the Beijing International Automotive Exhibition in Beijing, China, on Monday, April 25, 2016. Tesla Motors Inc. and BYD Co. are among manufacturers showing 147 new-energy vehicles at this year's show. (Photo by Qilai Shen/Bloomberg)

Students from St Andrews University indulge in a tradition of covering themselves with foam to honour the “academic family” on the lower college lawn on October 23, 2017, in St Andrews, Scotland. (Photo by Jeff J. Mitchell/Getty Images)

Supporters of Pakistan Tehreek-e-Insaf (PTI) party of Prime Minister Imran Khan shout slogans outside the Parliament House building in Islamabad on April 3, 2022. Pakistan will go to the polls to elect a new government within three months after Prime Minister Imran Khan foiled an attempt to boot him from office April 3 by getting the president to dissolve the national assembly. (Photo by Aamir Qureshi/AFP Photo)

A cow covered with foam scavenges in the waste left on the banks of the polluted Yamuna river in New Delhi on October 10, 2020. (Photo by Sajjad Hussain/AFP Photo)

A woman runs through a sea foam, as a seasonal cold front moved over the Cape Peninsula, following a week of severe weather and flooding in Cape Town, South Africa on June 19, 2023. (Photo by Nic Bothma/Reuters)

Children play among foaming bubbles that form an artwork by Roger Hiorns entitled A Retrospective View of the Pathway, at the Yorkshire Sculpture Park near Wakefield, UK on August 16, 2023. (Photo by James Glossop/The Times)