yī​kē​lǎo​shǔ​shǐ​huài​le​yī​guō​zhōu

one bad apple spoils the bunch

一颗老鼠屎坏了一锅粥 一顆老鼠屎壞了一鍋粥 yī​kē​lǎo​shǔ​shǐ​huài​le​yī​guō​zhōu
one bad apple spoils the bunch
Literally "one pellet of rat feces spoiled the whole pot of congee"; used to describe how a single small negative element can ruin an entire situation or group.

Cross-References

See