A calico sits in its enclosure and suns itself in Hessen, Germany on May 28, 2021. The Opel Zoo presents a walk-in Madagascar aviary for caltas and varis. The primate species is native to Madagascar and is threatened with extinction. (Photo by Andreas Arnold/dpa)

A teenager reacts as she receives a shot of the Sinovac vaccine for COVID-19 during a vaccination campaign at a school in Denpasar, Bali, Indonesia on Monday, July 5, 2021. (Photo by Firdia Lisnawati/AP Photo)

Creative imagery, gold winner: Sprats and Bread, Ruediger Schulz, Germany. (Photo by Ruediger Schulz/2021 Bird Photographer of the Year)

A Romanian honor guard soldier waits before the arrival of Moldovan President at Cotroceni Presidential Palace, in Bucharest, Romania, 23 November 2021. Maia Sandu is on a one-day official visit to Romania. (Photo by Robert Ghement/EPA/EFE)

Sakakibara Kikai's engineer Go Sakakibara poses with the bipedal robot Mononofu during its demonstration at its factory in Shinto Village, Gunma Prefecture, Japan on April 12, 2018. Developed at Sakakibara Kikai, a maker of farming machinery, LW-Mononofu is a 28-feet tall, two-legged robot weighing in at more than 7 tonnes. It contains a cockpit with monitors and levers for the pilot to control the robot's arms and legs. (Photo by Kim Kyung-Hoon/Reuters)

Two white storks stand close to each other on their nest on a tree in Zerbolo, Italy, Thursday, October 26, 2017. (Photo by Antonio Calanni/AP Photo)

MiG-15 jet fighters are pictured in Kucova Air Base in Kucova, Albania on October 3, 2018. Albania retired its 224 Soviet- and Chinese-made MiGs in 2005, and since 2009 NATO neighbors Italy and Greece monitor its airspace. That led to economic decline in and around Kucova, which was called “Stalin City” during the era of Communist rule. (Photo by Florion Goga/Reuters)

Students from St Andrews University are covered in foam as they take part in the traditional Raisin Weekend in the Lower College Lawn, at St Andrews in Scotland on October 22, 2018. The “raisin weekend” stems from a gift of raisins (now flour and foam) traditionally given by a first year student to their academic “parents” in gratitude for their guidance. (Photo by Russell Cheyne/Reuters)