A single magpie is considered a sign of bad luck. A Guide to the Scientific Knowledge of Things Familiar recites an old proverb concerning the incidence of bad weather when magpies forage alone and a possible scientific explanation for this.
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When you speak of bad luck, it is said that one should always knock on wood. Also knocking when speaking of good luck apparently helps with having good luck. This is an old Celtic tradition related to belief of wood spirits.
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Placing a hat on the bed is, apparently, bad luck. (South Carolina)
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An acorn should be carried to bring luck and ensure a long life.
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Some motorcycle enthusiasts hang a biker's bell from a portion of their bike to protect themselves from evil road spirits.
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Collect seven or nine different flowers on midsummer eve and place them under your pillow and it is said that you will dream of your future spouse. (Sweden)
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An acorn at the window will keep lightning out
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There are numerous sailors' superstitions, such as: it is considered bad luck for a ship to set sail on a Friday, to bring anything blue aboard, to stick a knife into the deck, to leave a hatch cover upside-down, to say "pig", or to eat walnuts aboard.
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