stir up a hornet's nest
To make many people angry; do something that many people don't like.
The principal stirred up a hornet's nest by changing the rules at school.
stir up
To bring (something) into being, often by great exertion or activity; cause.
It was a quiet afternoon, and John tried to stir up some excitement.
Bob stirred up a fight between Tom and Bill.
To cause (someone) to act; incite to action or movement; rouse.
The coach's pep talk stirred up the team to win.
When Mary heard what Betty said about her, she became stirred up.
The senseless murder of a small child stirred up the whole neighborhood.
The boss is in a bad mood today so don’t stir her up with any more customer complaints.