Giant panda Hao Hao sleeps at the Pairi Daiza Zoo in Brugelette, Belgium, on April 4, 2015. A pair of giant pandas from China, Xing Hui, the male, and Hao Hao, the female, was available to visitors again after the zoo reopened to public after the winter. The pandas from Sichuan Province of China arrived here in February 2014 and will stay for 15 years. Photo: Xinhua

Giant panda Xing Hui walks at the Pairi Daiza Zoo in Brugelette, Belgium, on April 4, 2015. A pair of giant pandas from China, Xing Hui, the male, and Hao Hao, the female, was available to visitors again after the zoo reopened to public after the winter. The pandas from Sichuan Province of China arrived here in February 2014 and will stay for 15 years. Photo: Xinhua

Giant panda Xing Hui eats bamboo at the Pairi Daiza Zoo in Brugelette, Belgium, on April 4, 2015. A pair of giant pandas from China, Xing Hui, the male, and Hao Hao, the female, was available to visitors again after the zoo reopened to public after the winter. The pandas from Sichuan Province of China arrived here in February 2014 and will stay for 15 years. Photo: Xinhua