The number of malpighian tubules differs between castes; in M. dispar, males have 16 tubules, queens range from 23 to 26, and workers have 21 to 29. Worker ants are usually the same size as each other, although this is not true for some species; worker ants of M. brevinoda, for example, vary in length from . The mandibles of the workers are long with a number of teeth, and the clypeus is short. The antennae consist of 12 segments and the eyes are large and convex. Based on a study on the antennal sensory of M. pyriformis, the antennal sensilla are known to have eight types. Large ocelli are always present. Queens are usually larger than the workers, but are similar in colour and body shape. The head, node, and postpetiole are broader in the queen, and the mandibles are shorter and also broad. Myrmecia queens are unique in that particular species either have fully winged queens, queens with poorly developed wings, or queens without any wings. For example, M. aberrans and M. esuriens queens are ergatoid, meaning that they are wingless. Completely excavated nests showed no evidence of any winged queen residing within them. Some species have queens which are subapterous, meaning they are either wingless or only have rudiments of wings; the queens can be well developed with or without these wing buds. M. nigrocincta and M. tarsata are "brachypterous", where queens have small and rudimentary wings which render the queen flightless. Dealated queens with developed wings and thoraces are considered rare. In some species, such as M. brevinoda and M. pilosula, three forms of queens exist, with the dealated queens being the most recognisable. Males are easy to identify due to their perceptibly broad and smaller mandibles. Their antennae consist of 13 segments, and are almost the same length as the ants' bodies. Ergatandromorph (an ant that exhibits both male and worker characteristics) males are known; in 1985, a male M. gulosa was collected before it hatched from its cocoon, and it had a long but excessively curved left mandible while the other mandible was small. On the right side of its body, it was structurally male, but the left side appeared female. The head was also longer on the female side, its colour was darker, and the legs and prothorax were smaller on the male side. Male genitalia are retracted into a genital cavity that