风吹草动

fēngchuīcǎodòng

风吹草动 — fēngchuīcǎodòng

1. lit. grass stirring in the wind; fig. the slightest sign of trouble or disturbance

   听到一点风吹草动，他就紧张起来。 tīngdào yìdiǎn fēngchuīcǎodòng tā jiù jǐnzhāng qǐlái — At the slightest sign of trouble, he became nervous.