Legend has it that the Romans also believed that conditions during the first days of February were good predictors of future weather, but the empire looked to hedgehogs for their forecasts.
These two traditions melded in Germany and were brought over to the United States by German immigrants who settled in Pennsylvania. Lacking hedgehogs, the German settlers substituted native groundhogs in the ritual, and Groundhog Day was born.
So have we've been using the wrong animal all these years? Should we instead say "Happy Hedgehog Day"? Link
(Image credit: Melissa Farlow/National Geographic)