Abstract: The possibility that some species of slaves might work more efficiently than others in slave-maker colonies was studiedusing colonies of the slave-maker ant, Protomognathus americanus (Emery, 1895) that contained two slave speciesTemnothorax longispinosus (Roger, 1863) and T. curvispinosus (Mayr, 1866). No difference between the contributionto foraging between the two species was found. This suggests that slaves of the less common slave species are not adjusting their behavior in the presence of another, more common slave-species.