Some bacteria deploy tiny spearguns to retaliate against rival attacks. Researchers at the University of Basel have mimicked attacks by poking bacteria with an ultra-sharp tip. Using this approach, they have uncovered that bacteria assemble their nanoweapons in response to cell envelope damage and rapidly strike back with high precision.

In the world of microbes, peaceful coexistence goes hand in hand with fierce competition for nutrients and space. Certain bacteria outcompete rivals and fend off attackers by injecting them with a lethal cocktail using tiny, nano-sized spearguns, known as type VI secretion systems (T6SS).