Bacteria commonly live in dense, multispecies communities where they constantly interact with other cells. This has led to the evolution of a multitude of social behaviours, ranging all the way from cooperation to lethal combat. In my talk, I will highlight a diverse set of social traits from across the spectrum of microbial interactions. I will show how bacteria cooperate with each other, how these behaviours affect the virulence of bacterial pathogens, and how cooperation evolves over time. I will also showcase the amazing diversity of mechanisms bacteria use to harm, inhibit, and kill their competitors. Some of these mechanisms even involve cell suicide, and I will talk about how these extreme strategies might have evolved. Most recently, we have also shown that certain kinds of attacks can be thwarted by a widespread bacterial trait – the production of “slime”.