A visitor feeds a food pellet to a giraffe in the Giraffe Centre in Nairobi, Kenya January 15, 2017. (Photo by Goran Tomasevic/Reuters)

A zoo staff feeds crocodiles as visitors look on at the Malabon Zoo in Malabon City, north of Manila, Philippines 21 December 2017. Wearing Santa Claus hats for the upcoming Christmas season, owner Manny Tangco (R, holding megaphone) and some select animals gave visitors a tour of the 28-year-old zoo. (Photo by Rolex Dela Pena/EPA/EFE)

Siberian Husky dogs of the Royev Ruchey Park team pull a rig during a practice session for the Karadag Sled Dog Rally on the frozen Mana River, with the air temperature at about minus 21 degrees Celsius (minus 5.8 degrees Fahrenheit), in the Siberian Taiga area outside Krasnoyarsk, Russia February 6, 2018. (Photo by Ilya Naymushin/Reuters)

A Sudanese girl with half painted face watches as protesters demonstrate outside the defense ministry compound in Khartoum, Sudan, April 25, 2019. (Photo by Umit Bektas/Reuters)

A great crested grebe feeds a chick sitting on its mother’s back on a lake in Cáceres, Spain. (Photo by Jose Luis Ruiz/Solent News & Photo Agency)

Mikhail Vasilenko, a participant from the Siberian town of Nizhny Tagil, works on an ice sculpture called “The Predator”, on the last day of the annual international festival of snow and ice sculptures “The Magical Ice of Siberia”, with the air temperature at about minus 28 degrees Celsius (minus 18.4 degrees Fahrenheit), in Krasnoyarsk, Russia, January 17, 2016. (Photo by Ilya Naymushin/Reuters)

People look at huge waves crashing on the San Esteban de Pravia seafront, northern Spanish region of Asturias February 8, 2016. (Photo by Eloy Alonso/Reuters)

Penitentes, or nieves penitentes (Spanish for “penitent-shaped snows”), are a snow formation found at high altitudes. They take the form of tall thin blades of hardened snow or ice, closely spaced with the blades oriented towards the general direction of the sun.