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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An acorn at the window will keep lightning out
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The superstitious symbolism of a black cat crossing one's path is dependent upon culture: some cultures consider this a sign of impending bad luck, while some cultures consider this a sign of impending good luck.
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Placing keys on a table is considered unlucky. (Sweden)
3
Before traveling a person should, apparently, sit on their luggage. (Russian)
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Placing a hat on the bed is, apparently, bad luck. (South Carolina)
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It is bad luck to put new shoes on a bed (or a table) (comes from the tradition of dressing a corpse in new clothes and shoes and laying them out so everyone can give their respects) - (UK)
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Once a wedding ring has been placed on the finger, it is considered bad luck to remove it.
117