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

A cosplayer poses for a photograph during the Comic Market 90 (Comiket) event in Tokyo Big Sight on August 12, 2016, Tokyo, Japan. Many manga and anime fans wearing cosplay lined up in the sun for the first day of Comiket. Comiket was established in 1975 and focuses on manga, anime, gaming and cosplay. Organizers expect more than 500,000 visitors to attend this year's summer event which runs for three days until August 14. (Photo by Aflo/Splash News)

A model presents a creation from the Fall/Winter 2017/18 collection by designer Lena Hoschek during the Mercedes-Benz Fashion Week Berlin, in Berlin, Germany, 17 January 2017. The Mercedes-Benz Fashion Week Berlin runs from 17 to 20 January. (Photo by Clemens Bilan/EPA)

Stray dogs stand on tombs in Diamond Hill cemetery in Hong Kong, China, 04 April 2017. According to the lunar calendar, the Qingming Festival is observed on 04 April . The Qingming Festival, also known as Tomb-Sweeping Day, is marked by Chinese people by going to the cemetery to cleaning up tombs, bring flowers, and making offerings to their ancestors. (Photo by Jerome Favre/EPA)

Sunrise over Haleakala Crater, Haleakala National Park, Maui, Hawaii on April 26th, 2011. (Photo by Robert Bush/Alamy Stock Photo)

Brittany Ching dressed as a character from the sci-film “Avatar” at the annual Denver Comic Con at the Colorado Convention Center on June 16, 2016. (Photo by AndyCross/The Denver Post)

In this January 12, 2016 photo, an abandoned boat lies on the dried up lake bed of Lake Poopo, on the outskirts of Untavi, Bolivia. Drought caused by the recurrent El Nino meteorological phenomenon is considered the main driver of the lake's demise. Along with glacial melting, authorities say another factor is the diversion of water from Poopo's tributaries, mostly for mining but also for agriculture. (Photo by Juan Karita/AP Photo)

A woman rides an electric bicycle on her way as she wears a sunscreen mask towards off strong ultraviolet rays in Fuyang, China on August 14, 2022. The Central Meteorological Observatory of China issued a high-temperature red warning. It is expected that the maximum temperature in some parts of China will reach above 40°C on August 14. (Photo by Sheldon Cooper/SOPA Images/Rex Features/Shutterstock)