Air pollution causes ant aggression

A new study published in the Proceedings of the National Academy of Sciences has found that pollutants in the atmosphere can affect chemical structures in ants, causing their nestmates not to recognise them. Exposure to pollutants even caused some ants to face aggression from their nestmates. 

Ants can distinguish between nestmates and non-nestmates by their uniquely structured cuticular hydrocarbons or CHCs. These chemical structures are unique to the colony the ant belongs to, but exposure to pollutants such as ozone can disrupt these structures by oxidising them.  

The ants in the experiment showed aggressive behaviour to ants who were exposed to ozone. These behaviours included biting and headbutting, as well as opening their jaws in a threatening display.  

Shockingly, ozone exposure also caused adult ants to abandon their offspring in 3 out of 12 colonies, suggesting that pollution may affect communication between ants and their larvae. The researchers mentioned that this may also be due to generally increased stress levels or immune system changes that arise as a result of ozone exposure.  

The study, by scientists from the Max Planck Institute for Chemical Ecology, found the effects of ozone exposure to be consistent across six different ant species. The findings may have more severe implications for ant species that live closer to human cities and forage during the daytime, as these species will be exposed to more ozone.  

This study builds upon previous research which found that exposure to ozone in fruit flies disrupted normal mating behaviour by affecting their pheromones, the chemicals which allow flies to identify potential mates. 

The findings are concerning because ants play important ecological roles in their ecosystems, contributing to pollination and reducing pest populations. With pollutant levels rising, ant colonies will not be able to carry out their roles as efficiently, as their social structures will be impaired.