A boy jumps into a pool of mud during the traditional “Bloco da Lama” or “Mud Street” carnival party, in Paraty, Brazil, Saturday, February 25, 2017. Legend has it the “bloco” was born in 1986 after local teens hiking in a nearby mangrove forest smeared themselves with mud to discourage mosquitoes and then wandered through Paraty. The party grew year after year, but revelers eventually were banned from parading in the colonial downtown after shopkeepers complained pristine white walls were stained with the hard-to-remove mud. (Photo by Mauro Pimentel/AP Photo)

Sumo wrestler Kaiho eats a “chanko” meal in Nagoya, Japan on July 18, 2017. After ending practice at 10:30 a.m., the wrestlers mingle with fans, sign autographs and pose for photos before the first of their two daily meals. (Photo by Issei Kato/Reuters)

Calves look out as they are transported in a cart in the village of Litkovka, in Omsk region, Russia on March 20, 2021. (Photo by Alexey Malgavko/Reuters)

A model presents a creation at a metro station during a show opening the Moscow Fashion Week in Moscow, Russia on October 22, 2019. (Photo by Evgenia Novozhenina/Reuters)

A resident removes mud on a street brought by monsoon rains in San Mateo, Rizal, Philippines, August 14, 2016. (Photo by Erik De Castro/Reuters)

A model takes a picture of photographers outside the Anna Sui show at the Strand Rare Book Room in New York on February 10, 2024. (Photo by Jeenah Moon for The Washington Post)

A boy rides on a snow wagon towed by a robot dressed as a Teddy bear, which only moves forward by moving its legs, during the Ice and snow carnival at Taoranting park in Beijing February 9, 2015. (Photo by Kim Kyung-Hoon/Reuters)

Brain-on-a-chip. Dazzling in green and magenta this image shows the nerve fibres (in green) produced by neural stem cells (in magenta) as they grow on a synthetic gel. Captured by a technique known as confocal microscopy, the image is part of research shedding light on how tinkering with the environment can affect the way in which nerve fibres grow. (Photo by Collin Edington and Iris Lee/Massachusetts Institute of Technology/Wellcome Images)