Acid spray helps ants keep their food disease-free

Abstract

A number of ant species produce acid in a poison gland in their abdomen to spray at enemies. Now it turns out that they also drink the acid to kill pathogens in their food. Because these ants often vomit up food to feed their co-workers, this helps prevent diseases spreading in colonies. Unlike vertebrates, insects don't usually have highly acidic substances in their stomachs. Here, Le Page discusses a study by Simon Tragust at the University of Bayreuth in Germany and his colleagues which found that species such as the Florida carpenter ant (Camponotus floridanus) increase the acidity level inside their stomachs by swallowing acid after eating. If ants were prevented from bending round to reach their poison glands, acidity levels were lower.