When solving difficult puzzles, Victorian Britons would employ snails. With all available clues written out on a piece of paper, these snails would trail over the page and eventually would fall off the edge. The clue with the most crossings of slime would be eliminated and over a period of hours the solution would be found. It is thought that in some areas of the Shetland Isles, this practice is still being used, but with spiders.