New research suggests ants use scents to tell each other apart and distinguish friends from potentially threating strangers.
In order for the society of ants and other insects to function, they must rely on chemical pheromones detected through sensors on their antennae to recognize other individuals, Cell Press reported. This new research demonstrates just how thoroughly ants can analyze these important chemicals using a broad-spectrum ability to detect hydrocarbons, and this trait may be unique to social insects.
"To our surprise, these very low volatility compounds are not only detected sensitively by specialized antennal sensors, but almost all of the hydrocarbon components are detected," said Anandasankar Ray of the University of California, Riverside. "Using this amazing high-definition ability to smell 'ant body odor,' the ants can recognize the various castes in the colony as well as intruders from another colony."
To make their findings, a team of researchers used a powerful electrophysiological method to systematically test the response of individual neurons in the ant antennae to hydrocarbons present in the cuticles of worker ants and their queens. Through this method, the scientists were able to determine which chemicals triggered a response in the ants' sensory system for the first time. This super-sensitivity to pheromones allows ants to detect even miniscule amounts of hydrocarbons so they can recognize each other in crowded colonies.
"This is a remarkable evolutionary solution for 'social networking' in large colonies," Ray said. "A more volatile body odor cue would be confusing to associate with an individual and could overwhelm the olfactory system of the colony members by constantly activating it."
The findings suggest the ants can respond to more than just the presence or absence of certain hydrocarbons, but also to the particular way in which various hydrocarbons are blended. This creates a sort of "barcode" that is unique to each ant.
In the future, the researchers hope to learn more about odorant receptors that detect pheromones in ant queens, which is believed to be a huge factor in colony organization.
The findings were published in a recent edition of the journal Cell Reports.
