jumpy from fear; afraid of every little noise
A yojijukugo describing a state of extreme fear where even the slightest sound or movement causes alarm. Often used in historical or literary contexts to depict panic or paranoia.
The routed soldiers were so jumpy that they were frightened by every little noise.
Both describe extreme fear, but 草木皆兵 emphasizes seeing enemies everywhere, while 風声鶴唳 focuses on being startled by sounds.
From the Chinese account of 苻堅’s defeat at the Battle of Fei River: the fleeing soldiers were so frightened that they mistook the sound of wind and cranes for pursuing enemy troops.