千里之堤,潰於蟻穴 [ㄑㄧㄢ ㄌㄧˇ ㄓ ㄉㄧ , ㄎㄨㄟˋ ㄩˊ ㄧˇ ㄒㄩㄝˊ; qian1 li3 zhi1 di1 , kui4 yu2 yi3 xue2] An ant hole causing the collapse of a great dike. Huge damage from a moment's negligence. (idiom) ◄ ►