In modern warfare coded messages are an important tool to ensure that units on the battlefield can co-ordinate their actions against the enemy and win the fight.
Scientists at UC Davis have found that bacteria use tiny protein messengers to co-ordinate their actions against victims and enemies.
In a study on bacteria feeding off rice-plants, a protein a called ax21 was found, enabling the bacteria to talk to each other in the event of an attack against the bacterial colony. The molecule is produced inside the bacteria and secreted, to tip off the other bacteria so they can line up in a phalanx, creating a bio-film surrounding the colony, protecting it against drying out or succumbing to antibiotics.
By working together and making individual sacrifice, they increase the survival-rate of the entire colony.