Panda worries US zookeepers by playing favourites with newborn twins – video

Giant panda Mei Xiang is worrying zookeepers at Washington DC's National zoo by focusing her care on the larger of her newborn twins. This behaviour is normal in panda mothers, so the keepers have a system. Every few hours they swap out the cubs, giving each one time to nurse and bond with its mother, while the other is kept warm in an incubator