The Centro Nacional de Investigación sobre la Evolución Humana (CENIEH) is organising the 13th Ratón Pérez Tooth Collection Campaign on Friday 25 September. For the first time, the event will be held at the Museum of Human Evolution (MEH), where members of the public will be able to donate milk teeth between 6 pm and 10 pm and help expand the Ratón Pérez Collection.

This citizen science initiative brings together deciduous teeth donated by the public to create a reference collection for anthropological, biomedical and forensic research. Milk teeth are a valuable source of information on growth, development and dental variation, making a large, well-documented collection essential for this type of research.

The donation process is straightforward. Participants simply need to bring the tooth or teeth they wish to donate to the dedicated collection area at the MEH during the campaign. Each tooth must be accompanied by information about the donor, submitted through a form, which must be completed by a parent or legal guardian if the donor is a minor.

All donor data are stored in a confidential database, while the teeth are preserved and used for scientific research in fully anonymised form. As in previous editions, and in keeping with the Ratón Pérez tradition, donors will receive a gift in exchange for their tooth, as well as a certificate acknowledging their contribution to the research carried out using the collection.

A growing collection network
The Ratón Pérez Collection is a scientific and citizen science project that has grown thanks to the involvement of thousands of families and numerous institutions organising tooth collection campaigns in Spain and abroad.
Campaigns have already been held in 2026 at the Spanish School of History and Archaeology in Rome (EEHAR-CSIC) and the University of Córdoba, where nearly 100 teeth were collected. Further campaigns will take place in September at the CSIC Delegation in Aragón, the Museum of Mummies in Quinto (Zaragoza), the University of Jaén and the University of Zaragoza, including its campuses in Huesca and Teruel.

The initiative will continue in November at the ALBA Synchrotron in Barcelona and Rey Juan Carlos University in Madrid, before moving to the CSIC Casa de la Ciencia in Seville in December. The CSIC Delegation in Galicia and the Sant Pau Research Institute in Barcelona will also take part, although dates for their collection campaigns have yet to be confirmed.

Some institutions also accept tooth donations throughout the year, including CENIEH itself and the University of Huelva. This continued public involvement is enabling the collection to keep growing and to generate new scientific knowledge.