In most ant colonies, one queen lays all the eggs, while a class system of worker ants collects food, takes care of the larvae, and goes to war … Only the males and the queen can reproduce, and the rest of the ants are sterile. When the queen dies, the nest also wilts. Very simple on its own, but it goes far beyond the pretzel of Harpegnathos – or the Indian jumping ant.
Within hours of the queen’s death, a frenzied “ritual battle” begins that can last up to a month. It’s a bit like a series of stabbing tournaments, where ants quickly punch each other in the face with their antennae. The multitaskers, who manage to duel and stimulate the ovaries at the same time, are victorious.
Then their impressive transformation into a “false queen” begins. The ovary of the victorious agent ant – about 5–10 per 100 colony – swells to five times its original size until it almost completely controls the abdomen. Their brains shrink by 25 percent, in order to reduce the ability of the brain to produce eggs.
Reproductive worker ants also produce a pheromone that prompts the rest of the colony to treat them royally. Moreover, their life expectancy increases between six months and five years, they stop producing the toxin and undergo some behavioral changes. Ultimately, mating can begin again and the future of the colony is secured.
The circle is round
This is amazing in its own right, but what makes this type of ant so special is that it can also reverse this process. If a queen-like worker ant falls off its base for any reason, it will return to old age and return to a full circle. The ovaries gradually shrink again, and the brain begins to grow – an unusual function previously unknown in insects.
“It provides opportunities to delve into the mechanisms that control whether the brain region grows or shrinks in size,” said Clint Pinnick, lead author of the study published on Wednesday in the journal. Proceedings of the Royal Society B: Biological Sciences.
Experience – he did experiments
Through an experiment, Penick and his colleagues attempted to trigger a metamorphosis by taking two false queens – “gamergates” in the terminology – from a sample of 30 colonies at a time. One of each pair was isolated in a plastic box for three to four weeks. The other 30 false queens that remained in the nest served as controls.
After a day or two, the lone ants stopped producing eggs, and after a few weeks they behaved like normal workers again. After six to eight weeks, the autopsy revealed that their internal organs had returned to their “normal” dimensions. And sure enough, their brains were bigger, too. It is not clear exactly why this happens. Scientists speculate that isolation stress may cause a chemical chain reaction.