What does the Tooth Fairy do with teeth?

4 November 2026

Nobody knows for sure, which means you get to decide. Popular answers are that the Tooth Fairy builds a sparkling castle from them, turns them into stars, or polishes them into fairy treasure. The best answer is one that suits your child and that you can keep consistent, so here are ideas, the real history of the legend, and what parents actually do with the teeth.

Answers to give your child

Children usually ask this after the first or second tooth, and they'll ask again. Pick one story and stick to it. Some favourites:

• She builds a castle. Every tooth is a brick in a shining white palace in Tooth Fairy Land. Very clean teeth go at the top where the sun catches them.
• She turns them into stars. The cleanest, brightest teeth are hung in the night sky. It's a lovely one to tell on a clear night while looking up together; see our guide to stargazing with kids.
• She makes fairy money. Teeth are the currency of fairyland, which is why she pays for them.
• She gives them to new babies. Old teeth are polished up and passed on to babies who are about to start teething.
• She keeps a museum. Every tooth is labelled with the child's name and the date, in a giant library of teeth.
• She grinds them into fairy dust. Which explains the glitter she leaves behind.

If your child asks a follow-up question you can't answer, turn it back to them: "What do you think she does?" Their answer often becomes the family story.

Why does the Tooth Fairy want teeth at all?

A simple answer for young children: baby teeth are precious because each one only grows once, and the Tooth Fairy looks after them so that nothing so special is ever thrown away. For children who like detail, the castle or museum stories give a reason she likes clean, well-brushed teeth best, which is a helpful nudge at bedtime.

Where did the Tooth Fairy come from?

The Tooth Fairy as we know her is fairly new. The earliest known printed reference is a short piece called "Tooth Fairy" by Lillian Brown in the household tips column of the Chicago Daily Tribune on 27 September 1908, suggesting that a child is more willing to let a loose tooth be removed if they know the Tooth Fairy will leave a small gift under the pillow. The idea spread through the 20th century and is now part of childhood across the UK.

Other countries have their own tooth collector, and many of them are mice rather than fairies:

• Spain and Spanish-speaking countries: Ratoncito Pérez, a little mouse. The Spanish writer Luis Coloma wrote a story about him in 1894 for the young King Alfonso XIII, who had just lost a tooth. Madrid has a plaque marking the mouse's fictional home.
• France: La Petite Souris, "the little mouse", collects teeth from under the pillow.
• Other places: in some countries children throw a lost tooth onto the roof or bury it, rather than leaving it under the pillow.

Children often love hearing that a mouse does the same job in other countries. It can also help explain why one friend got a visit from a fairy and another from a mouse.

A real-life tooth collection

If your child wants proof that someone really does collect teeth, here's a true story. From December 1958, scientists in St Louis in the United States asked families to send in their children's baby teeth. The Baby Tooth Survey, run by Washington University, Saint Louis University and a local citizens' committee, gathered more than 300,000 teeth before it ended in 1970. Scientists measured strontium-90 from nuclear weapons tests in them, and the findings helped persuade President Kennedy to sign the 1963 Partial Nuclear Test Ban Treaty with the UK and the Soviet Union. Children who sent in a tooth were given a colourful button badge.

It's a nice answer for an older child who has stopped believing but still asks: teeth can tell scientists a lot about the world a child grew up in.

What do parents actually do with the teeth?

Once the Tooth Fairy has "collected" it, the tooth is yours to keep or let go. Common choices:

1. Keep the first tooth only, labelled with the date, in a small box or baby book.
2. Keep them all in a tooth box with 20 compartments, or envelopes labelled by date.
3. Throw them away quietly, out of sight. Wrap them first, so they aren't found in the bin.
4. Return them later. Some families give the teeth back in an envelope as a keepsake when the child is grown up, perhaps with the Tooth Fairy's letters. See keepsake letters for children.

For ideas on making each visit special, see our Tooth Fairy ideas, and for wording, our Tooth Fairy letter ideas.