The 15,000 Volunteer Army: Inside the Largest Citizen Science Slime Mold Study

What happens when you send 15,000 living, brainless single cells to 15,000 different households? You get the world’s most ambitious study on microbial intelligence and climate resilience.

Led by Audrey Dussutour, a visionary researcher at the CNRS and the University of Paul Sabatier, the project “Derrière le blob, la recherche” represents a paradigm shift in how we conduct science. This isn’t just a hobbyist experiment—it is a massive logistical and scientific operation designed to answer a critical question: Can our planet’s oldest organisms survive the volatility of global warming?

The Scale: From 48,000 to 15,000

When the CNRS first announced the call for volunteers, they expected a modest response. Instead, they were flooded with 48,000 applications.

To narrow the pool to the final 15,000 participants, the team used a method fitting for the subject: biological randomization. Selection numbers were assigned to groups, and “blobs” in the lab were allowed to “choose” the winners by moving toward specific designated food sources.

The final army included:

• Schools and Universities: Integrating labs into the curriculum for thousands of students.
• Nursing Homes and Families: Engaging participants from age 7 to 97.
• Individual Hobbyists: Dedicated “blob-sitters” across France and beyond.

The Mission: Beyond the Animal Kingdom

Most climate change research focuses on “charismatic megafauna”—polar bears, elephants, and whales. But Dussutour’s mission was to shift the spotlight to the microbial foundation of life.

“Microorganisms are the fundamental gear that keeps the ecosystem running,” explains Dussutour. “By involving the public, we aren’t just collecting data; we are building a global literacy on the scientific method and the invisible reality of the microbial world.”

A Logistical “Blob-Factory”

Managing 15,000 volunteers is a feat of administrative heroism. Audrey Dussutour and her core team (Celine and Emily) exchanged over 20,000 emails and maintained a vibrant community through webinars and instructional videos.

But the real challenge was the physical logistics:

1. Mass Breeding: The lab was transformed into a large-scale breeding facility, requiring kilograms of oats and hours of labor every morning.
2. 60,000 Samples: Over eight months, the team prepared 60,000 individual samples for shipping.
3. The Sclerotia Strategy: Shipping active blobs is impossible—they would escape the envelopes. Instead, the team transitioned the blobs into sclerotia—a dormant, dried state that is stable for transport and can be “revived” by the volunteer with a single drop of water.

Real Science at Home

This wasn’t a “dumbed-down” project. Volunteers were required to:

• Strictly Standardize: Use identical agar-agar, the same brand of oats, and specific heating bulbs to ensure valid data.
• Control vs. Experimental: Each volunteer split their blob, keeping one half as a control and subjecting the other to specific temperature profiles.
• Human-Aided AI: Participants manually traced the contours of their blobs in photos to help train a machine learning algorithm, which processed nearly one million images.

Why It Matters

The project aims to determine if Physarum polycephalum can adapt to the dynamics of temperature change—sudden heatwaves versus gradual warming.

The end goal? A peer-reviewed scientific paper where every single one of the 15,000 volunteers is credited as a contributor. It is the ultimate proof that anyone, with a bit of oats and a lot of curiosity, can help solve the most complex puzzles of our planet.

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Are you ready to join the next wave of slime science? Check out our Getting Started Guide to begin your own lab at home.

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Origin and E-E-A-T

• Source: CNRS Report “Mon Blob à la maison” & CNRS News.
• Researcher: Audrey Dussutour, Ph.D.
• Location: CNRS / Centre de Recherches sur la Cognition Animale (CRCA).
• Date of Research: 2021-2022.