Charles Darwin, The Formation of Vegetable Mould, Through the Action of Worms, With Observations on Their Habits, 1881.
A proverbial can of worms was opened for me recently, and usually, such an occurence is not a welcome thing, especially when the worms have been tended and nicely packed away in their can for a couple of decades. But it made me think a little further about how the idiom became commonly used. The expression, a modern-day version of Pandora's box, is thought to have originiated in America around the 1950s, with fishermen who once opening their cans of worms had difficulty getting them back in the can. Growing up, we often stopped on our way fishing to buy little styrofoam containers of worms - great for catching sun perch in our little lake in East Texas. But we fished until all the worms were gone so I don't remember that it took much effort to put worms back into a container.
Worms are not just good for fishing, but amazing friends to have in the garden. Author Amy Stewart wrote an lovely little book about the marvels of earthworms, The Earth Moved: On the Remarkable Achievements of Earthworms, and the important impact they have on the planet. Gardeners know that if worms are found in the soil, it is often a good indication that the soil is fertile. Worms convert organic matter into nutrients that plants can use. They loosen the soil, making it easier for plant roots to grow and to absorb nutrients. Worms also oxygenate the soil and increase the movement of water through the soil. Too, they support additional wildlife in the garden as food for birds.
Perhaps my worms can stay out of the can for a while . . .