Bioassays were performed to determine the behavioral responses ofCoptotermes formosanusShiraki soldiers to ants or ant extracts.C. formosanusresponded differently to semiochemicals of different ant species. A significantly greater proportion of termite soldiers responded aggressively toPheidole megacephala(F.) than to other ant species. Termite soldiers were significantly less likely to respond aggressively toMonomorium floricola(Jerdon),Tetramorium simillimum(F. Smith), andOchetellus glaber(Mayr) than to other ant species. Termites avoided contact withO. glaberin 85.3% of trials, but only avoided contact with other ant species in 18% or less of trials. Termite soldiers were significantly more likely to respond to freshly killed ants than to solvent-treated ants of the same species. Termites also responded similarly to freshly killed ants and dead termites treated with ant extracts, indicating that termite responses were mediated, at least in part, by chemical cues. The ability ofC. formosanusto distinguish among different ant species on the basis of semiochemicals could be an adaptive response that allows them to recognize particularly threatening enemies.