stir (up) a hornet's nest
1. To create, provoke, or trigger a dangerous, troublesome, or complicated situation. The government's military interventions really just stirred a hornet's nest in the region.
2. To provoke or instigate a lot of very angry or offended reactions. The politician's off-the-cuff remark about pollution stirred up a hornet's nest among environmentalists.
Farlex Dictionary of Idioms. © 2024 Farlex, Inc, all rights reserved.
stir up a hornet's nest
Fig. to create a lot of trouble. (Fig. on stir something up .) If you say that to her, you will be stirring up a hornet's nest. There is no need to stir up a hornet's nest.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.
stir up a hornet's nest
 If you stir up a hornet's nest, you do something that makes a lot of people very upset and angry. He has been asking a lot of questions and stirring up a hornet's nest around town. I seem to have stirred up a hornet's nest with my article about the teaching of Shakespeare in schools. Note: Sometimes people just talk about a hornet's nest. It's not that companies are unaware of illegal software. It's more that they are scared of uncovering a hornet's nest — they would simply rather not know. Wasserman had no idea what a hornet's nest he was stepping into. Note: A hornet is a large wasp with a powerful sting. 
Collins COBUILD Idioms Dictionary, 3rd ed. © HarperCollins Publishers 2012