“The mouse stole your tooth” - was once said to an ukrainian child.
If the mouse gave something in return for the tooth, is unknown. 
But the children of today are looking forward to getting a gift from the mouse.
That's why our mice have big pockets on their dresses and trousers - for a tooth and a coin. 
Every nations has created its own “thieves” for teeth. In Ukraine it's the mouse. 
And if she remains, then the next generation can be told about this mouse that stole mommys or grannys teeth.  
It will fascinate the child, guaranteed! :-)