A photo released on October 18, 2019 by the Zoo Berlin show one of two giant panda cubs with its eyes open held by a zookeeper at the Zoologischer Garten zoo in Berlin, Germany. /VCG Photo

The pair opened their eyes six weeks after their mother, Meng Meng, a six-year-old panda, gave birth to the twin panda cubs on August 31, 2019. While the cubs are born in Berlin, they remain Chinese and must be returned to China within four years after they are weaned. /VCG Photo

On loan from China, Meng Meng and male panda Jiao Qing arrived in Berlin in June 2017. /VCG Photo