one bad apple can spoil the barrel

== English == === Etymology === From the observation that rot of a single fruit can spread to many fruit nearby. === Proverb === one bad apple can spoil the barrel One bad person or element can have a harmful influence on many others. Synonym: one bad apple can spoil the whole bunch ==== Related terms ==== bad apple bad egg rotten apple ==== Translations ==== === See also === if you lie down with dogs, you get up with fleas rotten to the core the fish rots from the head