《汉书·志·五行志中之下》
雨多而龟为孽，龟能生活在陆地上，小是最阴之物；鱼离开水就死，则是极阴之妖孽的表现。
雨以龟以孽，龟能陆处，非极阴也；鱼去水而死，极阴之孽也。
When turtles become pests because of floods, the turtles can live above land; small turtles are the yin of yin things; fish die when they are out of the water, which shows that they are at the far end of yin negative energy and thus become pests.