Konni Forest Division, located in the Western Ghats and on the banks of the Achenkovil River in the Pathanamthitta district, Kerala, has a rich history of forest-human interaction and a diverse range of fauna. No research studies have been carried out on the ant fauna in the Konni area of the Agasthyamala Biosphere Reserve to date. Ant diversity of Evergreen-forest, Teak plantation and Adavi Ecotourism areas in the Naduvathumuzhy range of Konni Forest Division were compared for a period of one year (October 2021 to September 2022). The exploration yielded sixty-four species of ants under 35 genera belonging to 7 subfamilies namely Myrmicinae, Formicinae, Ponerinae, Dolichoderinae, Pseudomyrmecinae, Dorylinae and Amplyponinae. Myrmicinae was the most abundant subfamily in all studied habitats. The highest ant diversity was found in evergreen forest habitats (47 species), followed by less disturbed teak plantations (36 species), and the lowest in altered and disturbed ecotourism (28 species) regions. Among the three environments, Sorenson's similarity index of ant species was highest between evergreen forest (0.602) and teak plantation, and lowest between evergreen forest and ecotourism (0.533). This finding gives an idea about the ecological sensitivities of ants in different habitats and can help in the planning of conservation programmes in this protected area.