Flexibility at the edge of chaos: A clear example from foraging in ants

Starting from a clear, experimentally verified, example of a flexible biological system - an ant colony -, it is hypothesized that adaptability is enhanced at the ''edge of chaos'', that is, in the vicinity of a point of instability. An ant colony exhibiting an appropriate combination of group and mass recruitment can adaptively switch to a newly introduced food source if it is richer: this is precisely the case of some species, such as Tetramorium caespitum, whose behavioral parameters are argued to be those characterizing the edge of chaos. Several simple models of foraging show the robustness of the argument.