The taxonomy of ant species in the genus Cardiocondyla is very confused due to the extreme difficulty in separating many species based on morphology alone. In Japan. one group of the species complex Cardiocondyla sl. kagutsuchi has both winged and wingless worker-like (ergatoid) males (dimorphic) whereas others have only ergatoid males (monomorphic). https://thebanyantreers.shop/product-category/bookends/