They fly by circles in the sky, flying into the cloud to catch worms to feed the nestling.The view of swifts in the morning and evening is indeed a unique ecological spectacle in Swallow Cave.

• 在天空盘旋飞舞，剪翠裁云，捕虫育雏，早晚观燕，确是燕子洞绝无仅有的一大生态奇观。