The stinging apparatus in Hymenoptera is a specialized case of morphological adaptation of the ovipositor. But many aspects regarding its morphology and mechanical performance remain poorly understood. This project aims to investigate shape variation and its functional implications in predatory ants of the subfamily Ectatomminae. We will combine x-ray microtomography with 3D geometric morphometrics and finite element analysis to describe the shape variation and understand the ability of the ant sting to withstand simulated forces. Our preliminary results show a directional variation related to the sting shape, varying from robust to slender. Modifications in the dorsal curvature of the distal portion of the shaft tend to increase the stress concentration near its tip while avoiding high stress on the sting base. Additionally, changes related to the articular process and ventral curvature of the shaft results in a high stress area in the bulb region. Furthermore, sting shape can improve its stiffness or prevent high stress regions depending on the angle at which the forces are applied. We expect our results to create a solid base in our understating of morphological evolution and diversity in ants, providing valuable information on shape variation and functional performance within an evolutionary context.