This paper is to be found in Animal Behaviour, Volume 123, January 2017, pp. 207–216. Could this be an extension of the mechanism of stigmergy? (H/T to Jerry Coyne).
We investigated tool selection in two species of Aphaenogaster ants by giving them the choice between different kinds of potential tools (natural and artificial objects). Ant workers showed a clear preference for certain materials to be used as tool objects. Tool selection was also shaped by familiarity with the material as ants developed a preference for artificial tools with a good soaking capacity that cannot be found in their natural environment. Our results indicate that ants of this genus have evolved unique foraging strategies and show plasticity in their behaviour.