A team of research scientists at the University of California has studied ant colonies and have made a startling discovery that ants use their strong smelling power as a tool to protect their colonies.

This study, published in the Cell Reports journal, found that these industrious creatures’ powerful olfactory senses help them to distinguish between the members of their own colony and those from outside. The research team led by Anandasankar Ray, an Indian-born scientist undertook this study to get a better understanding of the little-known communication powers of ants through the use and detection of pheromones.

Hitherto they were aware that ants communicate with each other through the use of hydrocarbon chemicals found on their outer shells or cuticles. The researchers discovered that ants have the most evolved set of powerful olfactory genes and they use it to not only sniff out pheromones, but also can very precisely identify and recognize members of their own colony and differentiate those that do not belong there.

The scientists employed a very powerful electrophysiology method to examine hydrocarbons of the queen and worker ants’ cuticles. They studied the responses of worker ants’ antennal neurons and how these neurons responded to the hydrocarbons. The team theorized that these two types of ants acted as pheromone cues and hence they chose to study them.

Kavita R Sharma, another Indian-born scientist in the University of California research team said that they had discovered that although these hydrocarbons are of very low volatility they were highly sensitive and could detect all the hydrocarbon components on the cuticles as well as the specialized ones on the antennal sensors. In fact, it is believed that the low validity actually facilitated accurate identification as a more volatile form could cause confusion to the ants’ olfactory system. The results on this study led them to believe that the specialized property must be unique to social insects to be used as form of protection from intruders.

The study further found that each cuticle had a combination of multiple cuticular hydrocarbons. The scientists felt compiling the exact composition of the blend could be very useful to code information on other non-colony and colony ants. This study was also able to disprove an earlier model proposed in 2005 which said that worker ants could only sniff out non-nestmates and could not know the hydrocarbons of their own nestmates. In this research, scientists found that worker ants could indeed identify mates from the colony and those from outside the colony.