Understanding species adaptations to human-modified ecosystems is central to evolutionary and conservation biology. It is essential to evaluate trait variations in populations that occur along environmental gradients to understand the adaptive potential of species to human-driven environmental change. We analyzed morphological trait variations in the workers of four common and phylogenetically distant ant species (Dinoponera quadriceps, Dorymyrmex goeldii, Pheidole radoszkowskii, and Ectatomma muticum) along disturbance and aridity gradients in the Caatinga dry forest. Ants were collected using pitfall traps in 20 0.1-ha plots distributed over an area of 213.75 km 2 .Up to five individuals per species were selected from each plot to measure eight morphological traits. Between-plot variability contributed considerably (~37%) to the total variability of morphological traits. This pattern of high between-plot variability was consistent across species and traits. Such morphological intraspecific variations between plots were not strongly related to the aridity or disturbance gradients.However, when ant morphology did respond to environmental change, the response was stronger to aridity rather than disturbance, and responses were most conspicuous in P. radoskowskii. Our results suggest that ants in the Caatinga may have substantial potential for morphological adaptation to environmental changes and that disturbance intensity and variations in aridity are not strong determinants of ant worker morphology despite influencing morphological variation over small geographical distances. These morphological variations are likely to represent key assets, by enabling individuals and population to inhabit the variety of habitats provided by Caatinga and to cope with upcoming changes in land use and climate.