When fishing boats sail by the sea near Cat Islet, numerous sea birds perching on the Islet immediately soar into the sky. They quiet down and go back to the Islet only after the boats are gone. Cat Islet, situated at the southwest side of Wang-an Island, consists of basalt. Few people set foot on it because its terrain is precipitous and its weather is unbearably hot in the summer. However, with plenty of fish in the nearby sea and oysters growing on its reefs, lots of birds are attracted here to dwell and breed.