a Ac. echinatior ant with a whitish cuticular coating (Photo T.R.S.). b SEM image of ant cuticle with crystalline coating. c Backscattered electron (BSE) image of a polished cuticular cross-section of an ant. This layer is brighter than the cuticle in backscattered electron (BSE) mode scanning electron microscopy (SEM), indicating that it consists of heavier elements and is continuous, covering nearly the entire surface. d BSE image close-up of a polished cuticular cross-section of an ant.