American artists have drawn criticism after making stunning, intricate sculptures by pouring hot liquid aluminium into anthills.

A woman runs through the early morning mist on Hampstead Heath on September 30, 2011 in London, England. Much of the UK is enjoying a spell of unseasonably hot weather which is expected to last into next week. (Photo by Dan Kitwood/Getty Images)

Afghan girl athletes perform Wushu on the top of a hill in Kabul, capital of Afghanistan, January 18, 2017. In the conservative Afghan society where people especially in the countryside deeply believe in the old traditions and don't allow their girls and female members of the family to go out of home, exercising sport in open is extremely risky, but a group of girls are broken the taboo and exercising Wushu on a hilltop where the temperature is minus 2 Celsius degrees. (Photo by Rahmat Alizadah/Xinhua/Barcroft Images)

Young girls carry containers filled with drinking water beside the railway station in Agartala, India, April 20, 2016. (Photo by Jayanta Dey/Reuters)

Girls rest on stairs at the China Digital Entertainment Expo and Conference (ChinaJoy) in Shanghai, China July 27, 2017. (Photo by Aly Song/Reuters)

A girl reacts during a rehearsal for the Independence Day military parade in central Kiev, Ukraine, August 19, 2016. (Photo by Valentyn Ogirenko/Reuters)

Girls ride on a donkey cart with grass for animals on the outside of Nangarhar province, Afghanistan May 19, 2015. (Photo by Reuters/Parwiz)

An Afghan girl harvests Cotton buds at a field on the outskirts of Balkh province, Afghanistan, November 15, 2014. (Photo by Sayed Mustafa/EPA)