Neutrophils belong to the first responders of our immune system. They circulate in our bodies and hunt in infected tissues to ingest, kill, and digest harmful pathogens. To become such effective killers in the very complex situation of an inflamed tissue, they work together as a collective. They release chemical signals to attract other cells to form clusters of cells and attack as a swarm. Researchers from the Max Planck Institute of Immunobiology and Epigenetics in Freiburg decipher the basic biology of neutrophil swarming and now show that the cells also evolved an intrinsic molecular program to self-limit their swarming activity. The study elucidates how swarming neutrophils become insensitive to their own secreted signals that brought the swarm together in the first place. This process is crucial for the efficient elimination of bacteria in tissues.