Literally meaning that an ant nest can cause a dam to collapse, used to warn that slight negligence or small mistakes can lead to major catastrophe.

literally meaning a thousand-mile dike can be destroyed by an ant hole; used to describe how a tiny mistake or a small amount of negligence can cause a huge catastrophe

literally, a dike of a thousand miles may collapse because of an ant hole; small problems or moments of negligence can lead to huge disasters or major losses if not addressed early