Opening a can of worms
"Can of worms" refers to a problem that, when addressed, leads to many more related problems.
To open a can of worms refers to create a complex, confusing, or troublesome situation by taking a specific action. For example, questioning a policy might "open a can of worms" with unintended consequences.
If you open a can of worms, you do something that will cause a lot of problems and is, on balance, probably going to cause more trouble than it's worth.
The idiom comes from the idea that when a can of fishing worms is opened, the worms are difficult to control and wriggle everywhere.
- Fixing a small computer bug that then reveals five new software problems.
- A conversation about a sensitive topic like politics or a controversial decision, which could lead to arguments.
- Giving a promotion that might seem to solve one problem but causes a backlash and more complaints from other employees.
