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

Aluminium ingots are stored at a foundry shop of the Rusal Khakassia aluminium smelter outside the town of Sayanogorsk, Russia, September 3, 2015. Russia's Rusal has decided to delay a decision on its possible first dividend since listing five years ago though its second-quarter core profit more than doubled thanks to cost cuts and a weaker rouble. (Photo by Ilya Naymushin/Reuters)

Cars drive under a rainbow near Bad Langensalza, Germany, Wednesday, November 2, 2016. (Photo by Jens Meyer/AP Photo)

Lea Meyer of Germany falls at the water in the women's 3000m Steeplechase heats at the World Athletics Championships Oregon22 at Hayward Field in Eugene, Oregon, USA, 16 July 2022. (Photo by Robert Ghement/EPA/EFE)

A protester raises her fist at the entrance of Highway 280 and S. 4th St. as people protest the killing of George Floyd in Minneapolis in downtown San Jose, Calif., on Friday, May 29, 2020. (Photo by Nhat V. Meyer/Bay Area News Group)

Rescue workers stand next to TK Bremen cargo ship which ran aground during a powerful storm, spilling oil off the coast of France's northwestern region of Brittany as it lies stranded on Kerminihy beach in Erdeven, on December 16, 2011. (Photo by Damien Meyer/AFP Photo)

A doctor performs surgery on an injured man with a part of an aluminium alloy fence through his chest after a car accident in Zhumadian, Henan province, China, September 15, 2014. The doctor managed to surgically remove the piece. (Photo by Reuters/Stringer)

Players of the USA celebrate in the dressing room following their team's victory in the 2019 FIFA Women's World Cup France Final match between The United States of America and The Netherlands at Stade de Lyon on July 07, 2019 in Lyon, France. (Photo by Maddie Meyer – FIFA/FIFA via Getty Images)