Tactics reminiscent of the early American frontier days are now being used in Vietnam. Lieutenant Commander Donald D. Sheppard, UBN, of Coronado, California, aims a flaming arrow at a bamboo hut concealing a fortified Viet Cong bunker on the banks of the Bassac River, Vietnam on December 8, 1967. (Photo by AP Photo)

Khansa, an eight month old critically endangered Bornean orangutan shows off it's two front-teeth, at the Singapore Zoo on Thursday, January 11, 2018 in Singapore. The Singapore Zoo is active with its breeding programs as part of its wildlife preservation efforts. This is the Zoo's 46th successful orangutan birth. (Photo by Wong Maye-E/AP Photo)

In this 2017 photo provided by Simon Pierce, Jonathan Green checks on a fin-mounted satellite tag on a whale shark in the Galapagos Islands area of Ecuador. Despite typically being bigger than a double-decker bus, the elusive whale shark has only tiny, almost useless teeth. It's also one of the least understood animals in the ocean. (Photo by Simonjpierce.com via AP Photo)

Gemma Sadler models a fabulous Georgian costume, including a wig made from flowers and foliage created by Florist of the Year Helen James, during the staging day for the 2021 Harrogate Autumn Flower Show at Newby Hall, near Ripon, United Kingdom on Thursday, September 16, 2021. (Photo by Danny Lawson/PA Images via Getty Images)

A mother holds her daughter who is injected with a dose of the Soberana-02 COVID-19 vaccine, in Havana, Cuba, Thursday, September 16, 2021. Cuba began inoculating children as young as 2-years-old with locally developed vaccines on Thursday. (Photo by Ramon Espinosa/AP Photo)

Performers entertain passengers at London Heathrow Airport's T3 on Monday, November 8, 2021, as the US reopens its borders to UK visitors in a significant boost to the travel sector. Thousands of travellers are jetting off on transatlantic flights for long-awaited reunions with family and friends. (Photo by Steve Parsons/PA Images via Getty Images)

A Sadhu or a Hindu holy man stands on the banks of the river Ganges before taking a holy dip during “Kumbh Mela”, or the Pitcher Festival, in Prayagraj, previously known as Allahabad, India, February 3, 2019. (Photo by Adnan Abidi/Reuters)

An Orthodox child is given an icy dip in a lake in celebration of Epiphan, near the village of Vorontsovka, some 20 km from the Kyrgyz capital of Bishkek, Kyrgyzstan, 19 January 2019. People believe that bathing in blessed waters during the holiday of Epiphany strengthens their spirit and body. (Photo by Igor Kovalenko/EPA/EFE)