The Bird and Mouse Mountain is located in the Loulan Yellow Earth Ridge Valley region, in a highland area where the sand is rolling. Because there are no large trees to build nests in, the birds have no choice but to use mouse holes to build nests and lay eggs. The mice use the birds as their alarm system to prevent eagles from attacking them. The mice live inside the hole, and the birds live outside the hole. They each raise their own offspring, and do not harm each other.
鳥鼠同穴之山，渭水出焉。
《山海經》