Ants restrained from undesired reproduction by peers
Normally worker ants are not supposed to mate. Their job is to build a hive and care for the hive queen’s offspring instead. But a new study showed that when worker ants actually break the taboo and reproduce, their peers sense special fertility chemicals and can physically attack them to stop the undesired mating. Scientists believe this is an elaborate way for ants to keep order in their primitive society, and can be used to study human cooperation.
Now, a new study published online on January 8th in Current Biology, explains just how the cheaters get caught red-handed. Experimental evidence shows that chemical hydrocarbons produced by those sneaky sorts are a dead giveaway of their fertility status.
The findings represent the first direct evidence that cuticular hydrocarbons are the informational basis for the ants' reproductive policing, said Jürgen Liebig of Arizona State University.
To test the idea in one ant species (Aphaenogaster cockerelli), Liebig and Adrian Smith, also at Arizona State, mimicked reproductive cheaters by applying a synthetic compound typical of fertile individuals on non-reproductive workers. That treatment attracted nestmate aggression in colonies where a queen was present, they report. As expected, it failed to do so in colonies without a queen where workers had begun to reproduce.
This system for catching cheaters plays an important role in maintaining harmony in the ant world, Liebig said, and it sets an example that we might learn from ourselves.
" The idea that social harmony is dependent on strict systems to prevent and punish cheating individuals seems to apply to most successful societies," he said.
"Understanding what mechanisms are employed within ant societies, which are perhaps the most successful and widespread among all animals, provides a model for understanding the fundamental basis of successful cooperation."