Like ant colonies foraging for food in different habitats, neutrophils must rapidly find and kill pathogens to limit the propagation of an infection and maximize the chances of host survival. Despite the critical role of neutrophils in pathogen clearance, little is known about how they find pathogens within the sea of host cells in early infection sites. Our project investigates collective search by neutrophils. Building on previous research from the Thiam lab showing how neutrophils migrate in complex environments and release neutrophils extracellular traps (NETs) during NETosis to kill pathogens, we ask how diverse neutrophil tactics for eliminating pathogens are associated with different search strategies, and how the physical properties of the environment determine the effectiveness of search. We will investigate the crucial role of neutrophils in innate immune response by leveraging the expertise in collective behavior from the Gordon lab and the expertise in neutrophil biology from the Thiam lab. Our project will inform the design of strategies to optimize neutrophil-mediated immune response with the goal of preventing infectious disease and improving human health.