If you don't smash egg shells witches use them as boats.
A childhood belief about witches

others believed things like this
- You must break the bottom of egg shells after finishing a boiled egg or witches will use them for boatsAnon
- I used to think shell macaroni was sea shells.— Don Northrup
- We were told that if you played with egg shells you would get worts !— GAJ
- I used to think that walnut furniture was made out of the shells.— Cambria Consuelo
- I used to believe that red pistachio shells were the same as women's press on nails.— Bob
- I used to think that a company had boats all over the world making waves, and airplanes making cloudsAnon