Hollydell Poseidon ridden by Madeline Reader-Smith takes part in the Shetland Pony Grand National Flat Race in Aid of Bob Champion Cancer Trust during day two of the Cambridgeshire Meeting at Newmarket Racecourse on Friday, September 28, 2018. (Photo by Mike Egerton/PA Wire)

The Duchess of Cambridge pulls a pint with the Duke of Cambridge during their visit to Belfast Empire Hall for an informal party to celebrate inspirational young people who are making a real difference in Northern Ireland as part of their two day visit to Northern Ireland on February 27, 2019. (Photo by Aaron Chown/PA Wire Press Association)

Wedges of an orange generate enough current and electrical juice – 3.5 volts – to power an LED. The fruit’s citric acid helps electrons flow from galvanized nails to copper wire in this 14-hour exposure. This image was published in September’s Visions of Earth, a trio of photos that appear in each issue of National Geographic. (Photo by Caleb Charland/National Geographic)

A murmuration of starlings above the the small village of Rigg, near Gretna, in the Scottish Borders, on November 25, 2013. The weight of the resting birds on power lines caused some power localised power outages in the village. Still one of the commonest of garden birds, its decline elsewhere puts it on the Red List of endangered species. (Photo by Owen Humphreys/PA Wire)

Karis, an 8 week old lion cub, growls at a pumpkin as she explores a Halloween treat put in her enclosure by staff at Blair Drummond Safari Park near Stirling, Scotland, Tuesday, October 29, 2013. (Photo by Andrew Milligan/AP Photo/PA Wire)

Karis, a one month old lion cub being weighed at Blair Drummond Safari Park near Stirling, Scotland, Thursday October 10, 2013. Weighing in at 5kg, the cub will stay with her mother, Teekay until she is 12 weeks old before they are returned to the pride. (Photo by Andrew Milligan/AP Photo/PA Wire)

New lovebirds boxer Robin Deakin – once known as “Britain's Worst Boxer” – and former UK “Big Brother” star Lisa Appleton go to the boxing gym in London, United Kingdom on September 28, 2016. The pair were seen holding hands in the street on arrival, and they then slogged it out in the ring and fooled about in Robin's gym. (Photo by FameFlynet UK)

An NHS worker walks past a banner supporting NHS staff outside Salford Royal Hospital on March 22, 2020 in Manchester, UK. Coronavirus (COVID-19) has spread to at least 182 countries, claiming over 13,069 lives and infecting more than 308,592 people. There have now been 5,018 diagnosed cases in the UK and 233 deaths. (Photo by Anthony Devlin/Getty Images)