Bdellovibrio bacteriovorous is a gram-negative bacterium that preys on other gram-negative bacterium including Escherichia coli . From our previous research, B. bacteriovorous was found to prey successfully on E. coli even when grown on filters at hydrated air-solid interfaces. Our next goal is to study B. bacteriovorous with native biofilms. We chose the E.coli ZK1056 strain because it easily forms a biofilm at air-liquid interfaces. In this investigation, we observed the effectiveness of B. bacteriovorous to break down the biofilm as it preys on the E. coli constituents of the biofilm under various conditions. We applied atomic force microscopy to this system to measure biofilm structure as a function of time and B. bacteriovorous is observed to perturb or destroy biofilms of E. coli . In addition, atomic force microscopy measurements of bacteria at surfaces are corroborated with serial dilution countings of bacteria in solution.