Notes on the predatory behavior of species ofCerapachys, Phyracaces, andSphinctomyrmex are given. All of the species thus far studied have proven to be myrmecophagous, feeding on the brood (and in some cases adults) of other species of ants. Raids are conducted by groups of workers and are usually of short duration. A foraging expedition ofPhyracaces cohici is described, during which the workers started out as a compact group but later dispersed into small groups and lone individuals deployed in a circular pattern around the home nest. On the basis of these observations there is suggested a hypothetical pattern of alternating foraging and raiding behavior, which is believed to result ultimately in an efficient exploitation by the ants of the surrounding territory. Notes on other phases of biology, including colony size and nest structure, are given.