In queenright colonies of the slave-making ant, Chalepoxenus muellerianus, workers formed dominance hierarchies through ritualized food begging and antennation bouts, but did not lay eggs. Within a few hours of the experimental removal of the queen, the frequency of dominance displays increased drastically and the interactions became considerably more violent. During the observation period, the dominant workers almost incessantly attacked subordinate slave-makers and slaves by antennation and biting. The aggression rate decreased after approximately 3–4 wk. Within a single colony, several high-ranking workers were observed laying eggs, although typically only one or a few top-ranking individuals became fully fertile Directly after eclosion, young workers engaged in aggressive interactions with other young workers and high-ranking old workers, but did not dominate the top-ranking egg-layers. Callows achieved ranks immediately below the top-ranking worker.