Petriskål (IMAGE) Aarhus University Caption In the laboratory, wood ants were allowed to wander on the right side of this petri dish. The ants and the bacteria and fungi on their legs secrete antibiotic substances that prevented apple rot fungus from growing on the part of the agar plate that the ants had access to. On the left-hand side, the fungus grows unhindered (the white cotton-like areas). Credit Ida Cecilie Jensen Usage Restrictions none License Original 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.