Native grass conservation buffers established for grassland birds require periodic disturbance, but disturbance of vegetation and soil may increase abundance and activity of imported fire ants (Solenopsis sp.). This is a concern because fire ants are invasive, often respond positively to disturbance and can be a major cause of nest losses in grassland birds. We experimentally tested if fire ant mound density and foraging activity increased after burning and disking in native grass buffers. In 2008, fall disking increased mound density and foraging activity during the first growing season post-disturbance, but burning did not. In 2009, disking had no effect, but effects of disking the previous season persisted into the second growing season. Prescribed fire, which tends to maintain or increase perennial grass cover, may be a better option than disking for managing native grass buffers where fire ant densities are high.