Giant panda Yang Yang plays with her twins in the Tiergarten Schonbrunn zoo in Vienna, Austria, Sept. 28, 2016. Initially the zoo thought mother Yang Yang had only given birth to one panda on August 7 because the delivery happened inside a dark nesting box and was only observed via an infrared camera. More than a week passed before zookeepers realized there was a second one. (Photo/Agencies)
