Bacteria are the most abundant and diverse lifeform on Earth, coating almost every surface, with the majority spending their lives in biofilms. This lifestyle is universally perceived as problematic since biofilms contribute significantly to equipment degradation, including billions of dollars yearly in DoD assets, through corrosion, mold, or increased drag. However, biofilms do not have to be a problem. New insights suggest biofilms could be rendered beneficial by redirecting their composition and structure. Similar to the Arcadian vision of harmony with nature, the DARPA Arcadia program will develop “probiotics” to protect military materials and equipment using naturally occurring microorganisms to generate robust and beneficial coatings.