Scent is essential to ant society: every ant within a colony wears the badge of membership in the form of smelly hydrocarbons. Human air pollution, a new study from Max-Planck Institute researchers suggests, is wreaking havoc on ant society by interfering with these characteristic scents. Each ant species' perfume is formed from stable alkanes, plus a colony-specific mix of alkenes. Unfortunately, these alkenes very easily react with ozone , an oxidant pollutant that has increased in the air