Buzz
When we say 'opening a can of worms' in a figurative sense, we mean tackling an issue that, instead of resolving things, ends up creating more confusion and difficulty. On a literal level, as any fisherman will tell you, opening a can of worms can lead to far more hassle than expected. It's no wonder the idiom is rooted in the actual experience of handling live worms.
The Oxford English Dictionary traces the phrase's first documented use to a 1962 article in the Times. However, multiple dictionaries and experts in slang and idioms point out that the expression likely emerged earlier in the U.S.; World Wide Words notes that it appeared in a Michigan daily newspaper as early as 1951.
Experts agree that the idiom 'can of worms' refers to a container for oligochaetes. Before plastic and styrofoam became widely used, bait shops commonly sold live bait in metal cans with handles and lids. One of the most sought-after types of live bait was (and still is) Canadian night crawlers, which are hand-collected from pastures and fields overnight. These worms are prized by fishermen targeting species such as walleye, catfish, and bass.
Worms aren’t the only creatures used as live bait. Anglers also rely on various creepy-crawlies like leeches, insect larvae, minnows, and crawfish to attract different types of fish.
The advantage of live bait is its liveliness; its wriggling movement on the hook entices fish. However, this very liveliness is also the disadvantage—if the container is left unsecured, you risk losing your bait. Worms, for instance, will often escape or make it tricky to get them all back in the can once opened. Once you've opened that can, you've got a real mess to handle.
