To open up a can of worms is a rather strange idiom used to describe a situation where you have created a problem through statement or action.
E.g. "I wish I’d kept quiet at the meeting; now I’ve opened up a right can of worms!"
It’s usually a situation that leads to more problems by exposing some difficult issues that people were avoiding. I guess the worms come out of the can and crawl all over the place bothering people.
Well, it’s pretty odd because I’ve never seen a can of worms in a supermarket. Although, I believe worms make a very nice omelette filling. Enjoy your meal!
Better still, worms are now used as part of a bio-recycling process so that's one can-o-worms that won't get you into bother.