Army ants are ingenious bridge builders using their bodies as a resource. The fascinating experiment was conducted by researchers with the University of Sydney, Australia.
Army ants of the genus Eciton dwelling on the Amazonian Barro Colorado Island were observed in their habitat as they build bridges using their own bodies. Their natural architectural talent has been on display for scientists trying to understand how their technique could be applied to robotics.
Army ants are ingenious bridge builders and their natural architectural talent is mirrored when they reach a gap in their route to food and resources so needed to keep the colony alive. Thus, using their own bodies, they bridge gaps in the road while at the same time calculating the shortest route and adapting to changes in the structure.
An algorithm skilfully underpins the army ants’ architectural endeavors. They are calculating costs of ant power and the benefits to be gained in real time, shifting the position of the bridge at any time it is deemed necessary, with the rest of the individuals in the bridge rapidly adapting.
The research paper featuring in the PNAS journal is an exciting read for anyone looking to gain a deeper insight on the decisions of the army ants when engaging in bridge building. Striking the right balance is of course important in such a complex endeavor. Christopher Reid, lead author on the study and postdoc researcher with the Sydney Insect Behavior and Ecology Lab stated:
“Indeed, after starting at intersection between twigs or lianas travelled by the ants, the bridges slowly move away from their starting point”.
The bridges create shortcuts to the food resources and lengthen with the addition of new army ants. However, there comes a point when the bridges remain suspended in mid-air. There is a sound fiscal thinking behind this surprising fact as well.
The more army ants join a bridge, the less army ants are patrolling the bridge and carrying resources across it. Having lengthened the bridge sufficiently to allow easier access, this may remain suspended if any individual is to be left to do the carrying.
Army ants are ingenious bridge builders while also being ferocious murderers. They attack the nests of wasps of other ants, scavenging for the larvae stored here and carry them away to be the colony’s nutritious snacks.
Building the bridge isn’t the last of the exciting findings of the study. According to the researchers, the ants feel the traffic across the bridge and know when it’s time to dismantle their impromptu creation and head back to their colony. At the same time, the gap that is to be bridged, as well as the starting points of the bridge are marked by pheromones.
Easy to sense by army ants of the same colony, they will react instantly by adding their own body to the architectural endeavor.
Photo Credits: Wikimedia