Phorid flies are selective parasitoids of fire ants (female phorid flies lay their eggs inside fire ant workers, and developing larvae feed on and eventually kill their host ants). Because fire ants are extremely invasive, phorid flies are actively studied for pest control; however, it is not known how the larvae behave inside their hosts. Using microcomputed tomography (microCT) to generate 3D x-ray images of infected ants, it is possible to determine the location of phorid fly parasitoids at different developmental stages.