A Chesterfield Borough Police telephone operator tests a gasmask with built in earpiece and microphone. The telephone service is considered one of the most important links in the coordination of ARP operations and must remain operational during air raids, 12th April 1939. (Photo by Fox Photos/Hulton Archive/Getty Images)

This picture taken on May 4, 2020 shows gentoo penguins chasing krill during feeding time in their enclosure at the Ocean Park theme park, which is currently closed due to the COVID-19 novel coronavirus, in Hong Kong. Save for an absence of gawping crowds, life for the penguins of Hong Kong's Ocean Park has been much the same during the coronavirus pandemic – but their carers have worked long shifts to keep the monochrome troupe healthy. (Photo by Anthony Wallace/AFP Photo)

A health worker dresses in a protective suit before starting to perform the coronavirus testing in an effort to stop the spread of the coronavirus disease (COVID-19) in the Kibera slum of Nairobi, Kenya, May 26, 2020. (Photo by Baz Ratner/Reuters)

Pigeons cool down at a public fountain on a hot summer day at University Plaza in downtown Bucharest, Romania, 10 June 2020. Temperatures in Bucharest reached 30 degrees Celsius. (Photo by Robert Ghement/EPA/EFE)

A model presents a creation from Dior's Cruise 2021 collection during a live-streamed runway show without an audience due to the coronavirus disease (COVID-19) outbreak, at the Piazza del Duomo, in Lecce, Italy on July 22, 2020. Christian Dior hosted a live but audience-free fashion show in the Italian city of Lecce, in a dazzling celebration of local crafts and traditions that included a dance spectacle in the middle of the baroque main square. (Photo by Alessandro Garofalo/Reuters)

Pham Thi Thanh drinks a glass of water used as a treatment during a medium ritual at a Hau Dong ceremony at Phu Day temple in Nam Dinh province, Vietnam, May 7, 2017. Dating to the 16th century, Hau Dong centres on a belief in the Mother Goddesses of three realms – forest, water and heaven. It draws from elements of Taoism, Buddhism and other religions. (Photo by Reuters/Kham)

Brittany Ching dressed as a character from the sci-film “Avatar” at the annual Denver Comic Con at the Colorado Convention Center on June 16, 2016. (Photo by AndyCross/The Denver Post)

A woman participates in an insect-eating competition at a scenic spot in Lijiang, Yunnan province, China June 25, 2017. Insects have been a part of Yunnan cuisine for centuries, long before their potential as sustainable sources of protein caught the eye of the Western world. Bee larvae, grasshoppers and cicadas are just some items found on menus in the region. (Photo by Reuters/Stringer)