Two large rats were scuttling around a glass cage meant for snakes. There was no official explanation for the change of exhibits, but one zookeeper said the lion had been sent away for breeding.
Meanwhile, two crocodiles are at large in Jiangsu province after the botched demolition of a breeding farm.
Six Nile crocodiles escaped when workers descended, in the middle of the night, to demolish the farm on the outskirts of Xuzhou city, claiming that the outbuildings had been erected without permission.
Four of the beasts, each roughly 2.5m long, were recaptured by farm managers.