千里之堤，溃于蚁穴
A Dam of a Thousand Miles Can Collapse Due to an Ant Hole
千里长的堤坝会因小小的蚂蚁洞穴而溃决。比喻细小的隐患，也会酿成极大的灾祸。出自《韩非子》。任何事物都有一个由小变大、积少成多的演进过程，如果期望事物向好的方向发展，就必须消除各种隐患与不利因素，不能因为它的细小而忽视其存在，必须早发现、早遏止。此语以比喻的方式，从反面申明了“防微杜渐”的道理。
This expression from Hanfeizi highlights how a minute hazard is capable of developing into a devastating disaster. Everything evolves from small to large or grows from few to many. If achieving a good result is expected, then all kinds of hidden risks and potential dangers must be detected and prevented as early as possible, no matter how negligible they may be. The saying illustrates by analogy the importance of early prevention.
引例 Citations：
◎有形之类，大必起于小；行久之物，族必起于少。故曰：“天下之难事必作于易，天下之大事必作于细。”是以欲制物者于其细也。故曰：“图难于其易也，为大于其细也。”千丈之堤，以蝼蚁之穴溃；百尺之室，以突隙之烟焚。（《韩非子·喻老》）
有形的事物，一定是由小变大的；时间久远的事物，一定是积少成多的。所以说：“天下的难事必定从简易开始，天下的大事必定从细微开始。”因此，掌控事物必须从细微时就着手。所以说：“谋划难事要从简易处入手，想做大事要从细微处入手。”千丈长的堤坝会因蚂蚁的洞穴而溃决，百尺高的房屋会因烟囱的缝隙冒出火星而焚毁。
Any living object grows invariably from small to large while any massive accumulation must have started small far back in time. Therefore, it can be said that any difficult job must begin from the easy part and any enormous undertaking must originate from a tiny beginning. Hence, to keep good control of things at hand, it is important to start with managing their small details. That is the reason why one should "start planning for a hard job with its easy part and start undertaking a big task bit by bit." A dam a thousand miles long can collapse by an ant hole and a building a hundred feet tall can be burned to ashes by fire escaping from a chimney crack. (Hanfeizi)
◎故百寻之屋，突直而焚燎；千里之堤，蚁垤（dié）而穿败。古人防小以全大，慎微以杜萌。（《晋书·陈頵（yūn）传》）
所以，八百尺高的房屋，会因为直通通的烟囱冒出火星而焚毁；上千里长的堤坝，会因为小小的蚁穴而溃决。古人在不好的事物尚处于细微阶段就开始防范，将其遏止在萌芽状态，为的是保全大的方面。
So a building a hundred feet tall can be burned to ashes by fire escaping from a chimney crack and a dam a thousand miles long can collapse because of an ant hole. Ancient people begin to take precautions when dangers are still negligible and try to eliminate them in their nascent stage so as to protect what matters most. (The History of the Jin Dynasty)
推荐：教育部 国家语委
供稿：北京外国语大学 外语教学与研究出版社
责任编辑：钱耐安
