put the cat among the pigeons
Definition from Wiktionary, the free dictionary
- (idiomatic) To cause alarm.
- Professor Stephen Hawking put the cat among the pigeons last week with his cheery remarks about comet Machholz-2, which some astronomers believe could be heading our way. — The Times, 19 September 1994
- Brewer's Dictionary of Phrase and Fable, Cassell, 1996