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)

Christian Bale poses for a fan at the 25th annual Screen Actors Guild Awards at the Shrine Auditorium & Expo Hall on Sunday, January 27, 2019, in Los Angeles. (Photo by Mario Anzuoni/Reuters)

A woman tries to catch snowflakes with her tongue during a snowfall on Chandragiri Hills in Kathmandu, Nepal on January 23, 2019. (Photo by Navesh Chitrakar/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)

A Felix the Cat balloon and other parade floats and balloons are led down Broadway during the annual Macy's Thanksgiving Day Parade; ca. 1900s, Broadway, Manhattan, New York City, New York State, USA. (Photo by Underwood & Underwood/Corbis)

Lowry Park Zoo elephants Matjeka, 23, and her 1-year-old daughter, Mavi, apply a liberal coating of “sunscreen” to themselves in a clay mud wallow at the park Tuesday, August 12, 2014, in Tampa, Fla., on the park's first observation of World Elephant Day to raise awareness of the wild African elephant crisis. “Elephants are prone to being sunburned”, said associate curator Chris Massaro. “What they need is lot of mud or clay to roll around in and cover up their skin so it will protect it from the sun”. (Photo by Cherie Diez/AP Photo/The Tampa Bay Times)

A baby otter has its first health checkup at Chester zoo, England on May 2, 2018. It was among five pups being weighed and microchipped. (Photo by Peter Byrne/PA Wire)