New research shows that bacteria deceive others for their own benefit but will co-operate for the good of their family.
The researchers at the Universities of Edinburgh and Nottingham have found that bacteria can cheat their way out of responsibility and avoid contributing to group efforts as a whole.
The cheating bacteria fails to contribute to the group, all the while saving its resources and benefiting from the efforts of others. But the research, in the journal Nature, also shows that bacteria, like animals, tend not to cheat when dealing with relatives.
This is believed to be because co-operation with kin helps promote their family DNA.
Scientists believe the research will help develop an understanding in how infections spread and how diseases evolve.
Stu West, of the university's School of Biological Sciences, said: "Bacteria can behave selfishly within their social circle.
"They cheat and lie to take advantage of others - but they also show loyalty to relatives."