Queen-specific signals and worker punishment in the ant Aphaenogaster cockerelli: the role of the Dufour's gland

► We studied the queen's Dufour's gland in the ant Aphaenogaster cockerelli. ► The Dufour's gland contains a queen-specific signal. ► Queen Dufour's gland contents direct worker aggression at competitive reproductives. ► Directing worker aggression is a function of the gland found among ants.