In South America, many species of Pseudacteon exist sympatrically. In Alabama, only two species of Pseudacteon are established: Pseudacteon curvatus and Pseudacteon tricuspis. Very little is known about Pseudacteon behavior in its native South America and even less is known about Pseudacteon behavior in Alabama. P. tricuspis is established at seven sites on populations of the red imported fire ant, Solenopsis invicta, and P. curvatus is established at four sites on populations of a hybrid fire ant (S. invicta x Solenopsis richteri). In South America, several species of Pseudacteon are often found at the same site and exhibit at least three behaviors that help explain how resources are partitioned: 1) fly species attack different size fire ant workers, 2) they select different periods of diurnal activity, or 3) they attack fire ants engaged in different activities. The dirunal activity of the two species of phorid fly that have been introduced into Alabama's imported fire ant populations were documented in an effort to improve current management strategies. In Alabama, P. tricuspis is still active late into the evening, until approximately 1800, extending ovipositional activity into hours when Psuedacteon litoralis is usually active in Brazil.