The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D. Copyright (C) 2007 by HarperCollins Publishers. Cite This Source
Idioms and Phrases with can worms
A complex unexpected problem or unsolvable dilemma, as in Tackling the budget cuts is sure to open a can of worms. This expression alludes to a container of bait used for fishing, which when opened reveals an inextricable tangle of worms.