Male-male competition in ants (Hymenoptera: Formicidae)

Aspects of male mating behavior in ants have been largely ignored in research until recently. Mating in ants is usually a short episode at the beginning of their life, often in large, anonymous swarms; therefore it has been argued that the potential for male-male competition is limited. Despite of this, several earlier studies on mating in ants described that males heavily compete for female sexuals, indicating pre-copulatory male competition. In the last few years, more and more studies investigating post-copulatory competition have been conducted, and they revealed fascinating examples of male traits to gain fertilization advantages over other males. Ant species exhibiting intranidal mating have been researched thoroughly, providing new insights also into pre-copulatory conflicts. We review what is known so far on male male competition in ants. Further studies may uncover additional unknown male competitive tactics and provide a better understanding of sexual selection in ant males, and we believe these studies offer an ideal system to compare male competition in social and non-social insects.