A study conducted by Princeton University together with researchers from the New Jersey Institute of Technology has found that ants can build a bridge made up of the bodies of worker ants. This enables other ants to cross over, by stepping on the bodies of their compatriots. The study focused on the army ant Eciton hamatum.
The laboratory based studies succeeded in creating bridges some 10 to 20 ants in length. The research group think the ants are capable to mimicking this response within the natural environment, either across short gaps or along streams. The researchers have called the bridge a form of “collective assemblage.”
According to Laboratory Roots magazine, the ants achieve this bio-engineering feat due to having tiny “interlocking” hook spikes on their legs. These hooks connect up to the hooks on the legs of other ants, to create a network or interlocking structure similar to many children’s toys.
The interlocking bridge is very stable and does not appear to buckle. It is based on the relatively high strength of the ant. In the study, the structure remained in place until all of the worker ants had crossed, the bridge ants then dispersed.
Speaking with BBC News, one of the lead researchers, Professor Nigel Franks noted: “This is an elegant, quantitative study of the wonderful adaptive abilities of army ants. The army ants are such effective raiders that they deplete their prey as they go. They are here today, gone tomorrow. Using their bodies to build dynamic bridges and to cover potholes in their route makes sense to them, as opposed to spending time and energy bulldozing obstacles out of their way.”
The research is published in the journal Proceedings of the National Academy of Sciences. The paper is titled “Army ants dynamically adjust living bridges in response to a cost–benefit trade-off.”
