Marines finish a 10 kilometer training hike carrying 55 pound (25 kg) packs during Marine Combat Training (MCT) on February 22, 2013 at Camp Lejeune, North Carolina. Since 1988 all non-infantry enlisted male Marines have been required to complete 29 days of basic combat skills training at MCT after graduating from boot camp. MCT has been required for all enlisted female Marines since 1997. About six percent of enlisted Marines are female. (Photo by Scott Olson/AFP Photo)

In this April 2, 2015 photo, dog owner Laura Aquilina strolls with her two year old Rottweiler Brutus, who was recently fitted with prosthetics on all four paws, and is currently learning to use them, near Aquilina's home in Loveland, Colo. Brutus lost all four paws to frostbite as a puppy while under care of a breeder, and Aquilina began caring for him about a year ago. (Photo by Brennan Linsley/AP Photo)

This artist image released from Japan's airline All Nippon Airways (ANA) on April 17, 2015 shows ANA's Boeing 787-9 aircraft into the colors of R2-D2 robot of Star Wars. Japanese air carrier ANA will place the special colored jetliner in service in this autumn. (Photo by AFP Photo/All Nippon Airways)

People in costume take photos during a Halloween event on October 31, 2015 in Lan Kwai Fong, Central District, Hong Kong. Halloween, a named taken from 'All Hallows' Even' falls on the day before All Saints' Day on November 1, a holiday when Christians remember their deceased loved ones. (Photo by Jerome Favre/Getty Images)

A boy listens to a prayer before he and other relatives visit the grave of their loved ones, all minors, who were killed a year ago during the government's war on drugs campaign, at the Tala Cemetery in Caloocan, east of Manila on December 28, 2017, as the world commemorates Holy Innocents' Day. Catholics celebrate the biblical passage when King Herodes the great ordered to kill all newborn babies to kill Jesus Christ. (Photo by Noel Celis/AFP Photo)

Clowns and entertainers gather to attend an annual service of remembrance in honour of British clown Joseph Grimaldi at All Saints Church in Haggerston in London, Britain, February 5, 2017. (Photo by Toby Melville/Reuters)

A man takes a picture of the first A380 for All Nippon Airways (ANA) during its delivery ceremony at the Airbus delivery center in Colomiers near Toulouse, France, March 20, 2019. (Photo by Regis Duvignau/Reuters)

A photographer in Somerset, South West England captured the mating rituals of toads as several males attempt to mate with one female all at once. (Photo by John Waters/NPL)