Species of Calomyrmex forage individually on low vegetation where they tend Hemiptera to collect honeydew as well as visit flowers and extrafloral nectaries to collect nectar and plant secretions.  They only occasionally return to their nests with dead insects or other prey, and apparently do not attack living arthropods.  During warm periods they may limit foraging to the cool morning and afternoon and during cooler weather they may only forage during warmer times of the day.  Nests are in soil with a single small entrance which is sometimes surrounded by a low mound of bare ground.
When disturbed, these ants secrete white to bright orange fluid from the base of the mandibles.  The colour of the secretions changes with the age of the worker, varying from white in young workers to dark orange in the oldest workers.  These secretions have several roles.  They act as an alarm signal to other ants in the area, as a defensive compound because of its viscous nature when exposed to air, and as a repellent to enemies or predators because of its repugnant properties.  Its repellent properties are so strong that even small mammals will avoid these ants.