Group and Mass Recruitment in Ant Colonies: the Influence of Contact Rates

The influence of contact rates on the efficiency (the ability to exploit a profitable environment) and flexibility (the ability to track down a changing environment) of foraging in ants is studied theoretically in the case where foraging relies on a mixture of group and mass recruitment. It is shown that a combination of efficiency and flexibility can be reached across a range of group sizes if (1) mass recruitment is combined with a low level of group recruitment, and (2) contact rates are weakly regulated. These results are discussed in relation to empirical work.