Foraging members of Pharaoh ant colonies guide fellow foragers away from unrewarding routes via a repellent pheromone.

“Forager ants lay attractive trail pheromones to guide nestmates to food1, 2 but the effectiveness of foraging networks might be improved if pheromones could also be used to repel foragers from unrewarding routes3, 4. Here we present empirical evidence for such a negative trail pheromone, deployed by Pharaoh’s ants (Monomorium pharaonis) as a ‘no entry’ signal to mark an unrewarding foraging path. This finding constitutes another example of the sophisticated control mechanisms used in self-organized ant colonies.” (Robinson et al. 2005:442)

Last Updated August 18, 2016