In comparison to other ant species like "Anoplolepis gracilipes", which rapidly take over areas they have been contained in, red imported fire ants are fairly easy to control. The first proposals to controlling the ant occurred in 1957 when the United States Congress authorised an eradication program using federal and state funding. Research on the ant and its biology has been continuous after the establishment of an eradication program, and many chemicals were used to eliminate them. However, scientists discovered that these insecticides were killing native fauna, and the Environmental Protection Agency subsequently outlawed them. Some scientists even questioned whether the ants were pests or not. Today, it is unlikely that the red imported fire ant will be eradicated in areas such as the United States. Populations can be managed properly if an integrated approach is used. Some scientists have considered using the ants' natural enemies against it; this includes "Kneallhazia solenopsae" and "B. bassiana". Phorid flies have also been viewed as potential biological agents, as they can reduce foraging activity in red imported fire ants and affect population levels. However, they are unable to affect colony growth rate. In addition, parasitic ants, parasitic wasps, mites, other pathogens, nematodes, and fungi have been considered to be potential biological agents. Others suggest that populations can be maintained or reduced by manipulating several ecological factors.