Bacterial Colonies (IMAGE) University of Oxford Caption Two bacterial colonies fighting on solid media using toxins. Upon detecting an incoming attack from the red strain, cells of the bottom strain pass this information on to others in the colony leading to a massive collective attack against the red strain. Green colour indicates toxin production. Credit Kevin Foster Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.