Cardiocondyla species generally nest in soil while a few nest in rotten wood on trees or even in hollow grass stems.  They forage on the ground surface or occasionally arboreally.  Because of their small size and habit of moving slowly, they are often overlooked.  Several species are well-known pests in tropical regions throughout the world. All of the 4 or 5 species found in North America are introduced from the Old World.  These are small "tramp" ants, commonly transported via commerce, especially in potted plants. Males of some species are wingless and worker-like ("ergatoid") and in a few both normal, winged males as well as these wingless forms are found.  Worker-like males fight among themselves until only one survives in the nest.