Ant Pupae Make Sounds to get Higher-Priority Status

A new study finds that ant pupae make audible sounds in order to maintain their status in their colony's hierarchy.

Social insects are known to use chemical pheromones to identify each other and to organize complex behaviors such as swarming. It is also known that ants make audible sounds. But it was not clear whether the sounds made by the ants actually meant something.

Now a new study has found that the ants emit sounds to get higher-priority status in their colony's hierarchy. A team of researchers from Centre for Ecology & Hydrology (CEH), University of Oxford, and University of Turin analyzed the sounds made by ant pupae. They found that the pupae made sounds similar to adults with their "file and scraper" organs. The sounds were emitted as single pulses and not longer sequences.

Interestingly, the research team found that the pupae make sounds to be assigned priority over younger, larval siblings. When unstressed adult worker ants hear the noise from the pupae, they would give them precedence over silent pupae in rescue operations back to the nest.

The findings provide evidence that ants can communicate through sounds, in addition to using chemical cues. Researchers also confirm that ants can send and receive signals across multiple information "channels".

"It seems highly likely that, in some situations, one type of signal might mediate the response to another," said Karsten Schönrogge, of the Centre for Ecology & Hydrology. "The implications of this additional layer of flexibility need to be explored."

The findings of the study, "Ant Pupae Employ Acoustics to Communicate Social Status in their Colony's Hierarchy", are published in the journal Current Biology.