A method for controlling a population of social insects such as ants, wasps or cockroaches by administering to a minor fraction of the population an effective amount of a composition that includes a bait and a 1-phenylpyrazole-type compound, particularly 5-amino-3-cyano-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-[(trifluorom- ethyl)sulphinyl]-1H-pyrazole.