Before , `` army ant '' meant ants from 5 different ant subfamilies : in two of these subfamilies , the Ponerinae and Myrmicinae , it is only a few species that show legionary behavior ; in the other three subfamilies , Ecitoninae , Dorylinae , and Leptanillinae , all of the species are legionary . Historically , `` army ant '' referred , in the broad sense , to various members of 5 different ant subfamilies : in two of these cases , the Ponerinae and Myrmicinae , it is only a few species and genera that exhibit legionary behavior ; in the other three lineages , Ecitoninae , Dorylinae , and Leptanillinae , all of the constituent species are legionary .