Bacteria respond to conflict much the same as humans do – by going to war with the competition – a study published in Current Biology says. Studying pairs of strains of E. coli, the researchers found that each strain used a toxin to poison the other when it came to competing for space. The toxin produced by one strain would not harm its own members but would be toxic to other strains. Hence this behaviour was seen as a war between the two strains. This is used by the bacteria to establish themselves, for example, in the human gut. Members of different strains varied in the intensity of attacking which varied from hyper-aggressive to passive. While this is known in animals, this is the first such study to see such behaviour among bacteria.