Dinomyrmex gigas - Major Worker (head detail)

Note: purchased specimen.

Here's a series of images documenting Dinomyrmex gigas, one of the largest ants in the world. This species is nocturnal, therefore only incidentally spotted by day.

This is a Major worker, sometimes just called "Major". Majors are sterile females tasked primarily as body guard for the rest of the colony when they go out at night to forage. Majors are significantly larger than minor workers, and have a heart-shaped massive head and giant mandables. They are described to grow to 28mm, whilst this one was even larger, at exactly 30mm.

These female soldiers alternate between deadly force and ritualistic violence. When defending against other species, it's total war leading to regular death. No time is wasted on mourning as a subsitute troup of Major follows.

However, when a Major meets another Major of the same species from a rival colony, something fascinating happens. They engage in ritual fights. They drum their feet in anticipation. As soon as one touches the other, it's game on, like boxers hitting first gloves. A ritual of intimidation follows, where antennae vibrate, mandibles are raised, and rapid front legs peddle like in a kangaroo fight.

The indivual to sustain the longest, wins. Yet only this round. The loser retreats to recover, clean and recharge. And then will return to the same tournament spot for another go at it. The animals will keep doing this for up to one month, probably because one realizes a lack of a end game.