It All Started Because of His Friend’s Horse
His friend wondered why her horse kept rolling in the dirt every spring, and David wanted to get to the bottom of it. He began wondering if the animal was trying to coat itself with a substance in the soil on purpose. After much-needed research, David figured out that his friend’s horse was covering itself with special bacteria species in the Nitrosomonas genus, which lives on a wide variety of invertebrates and vertebrates.