Throwing baby teeth on the roof?!

Is there a custom or tradition when a baby tooth comes out in your country? Is the tooth fairy coming?

In Japan, there is a custom of throwing baby teeth on the roof. - Yes, maybe you are shocked!
Throwing baby teeth on the roof is a custom/tradition to wish for permanent teeth to grow strong in Japan.

The origin is thought to be that mice are believed to live under roofs and rims, so that by giving baby teeth to mice, Japanese people hope that strong teeth will grow.
It's common to throw the lower baby tooth on the roof and the upper baby tooth under the edge.

In Japanese old stories or Anime of Japanese old stories, there are scenes where mice eat your food or mice eat your house. People in the past had an image that the teeth of mice were so strong.

Having said that, many people live in condominiums and apartments these days, so it's sometimes physically difficult to throw them on the roof anymore.

When I was a child, every time my baby tooth fell out, I went to my grandparents' house and threw the baby tooth on the roof.