rattle somebody's cage

rattle (one's) cage

To purposefully anger, upset, or unnerve one, especially to affect their performance or undermine their credibility. He makes a point of taunting his opponents before each match in order to rattle their cage. The audience member asked a number of embarrassing questions about her past in an obvious attempt to rattle her cage.
See also: cage, rattle

ˌrattle somebody’s ˈcage

(informal) annoy somebody: Who’s rattled his cage? OPPOSITE: smooth (somebody’s) ruffled feathers
See also: cage, rattle