The queen ant functions as the sole reproductive engine of the colony, making her presence indispensable for long-term survival. Her primary task is the continuous production of eggs, which generate the new generations of worker ants necessary for the colony to function. In the vast majority of ant species, her lifespan is directly linked to the colony’s existence; if she dies, the colony is effectively condemned. She is the only member capable of producing fertilized eggs that develop into female worker ants.
The Immediate Pheromonal Collapse
The death of the queen triggers an immediate chemical shockwave throughout the colony. The queen constantly produces a complex blend of chemical signals, known as queen pheromones, which are distributed among workers through physical contact and grooming. These pheromones confirm her reproductive status and regulate the behavior of thousands of workers, primarily by suppressing the development of worker ovaries. The sudden disappearance of this constant chemical signal acts like an emergency alarm. This loss of regulatory chemistry disrupts the normal division of labor and physiologically activates the workers, preparing them for a reproductive attempt of their own.
The Irreversible Decline of the Colony
For most single-queen species, the death of the reproductive female sets the colony on a slow, irreversible path toward extinction. The core of the problem is demographic: the loss of the queen means the immediate cessation of new worker production. While the colony may appear to function normally for a time, the existing population of worker ants begins to age without replacement. Worker ants have relatively short lifespans, and as the current workforce naturally dies off, the colony’s population dwindles, reducing its capacity to perform necessary tasks. An inability to effectively forage for food, defend the nest, or maintain the nest infrastructure eventually leads to a functional collapse.
Worker Reproduction: A Last Attempt
In response to the pheromonal vacuum, many worker ants activate their dormant ovaries, leading to a desperate, last-ditch reproductive effort. Female worker ants retain the ability to lay eggs, but lacking the specialized organ to store sperm, the eggs they produce are unfertilized. Due to the haplodiploid sex determination system, unfertilized eggs develop only into male ants, known as drones. Producing a generation of males is a biological dead end for the colony’s survival, as drones are non-functional members of the workforce. Their only purpose is to fly away to mate and spread the colony’s genetics one last time before the nest collapses entirely.
Colonies That Can Survive
The dire fate of a queenless colony is not universal across all ant species, as a few biological strategies allow for survival. The most common exception is found in species that exhibit polygyny, meaning their colonies naturally contain multiple egg-laying queens. In these cases, the death of a single queen is easily absorbed, as the remaining queens continue to lay eggs and maintain reproductive output. A rarer mechanism involves the production of a replacement queen, sometimes called a gamergate or pseudoqueen. In certain species, workers can engage in ritualized duels to determine a reproductive successor, who then undergoes physiological changes to take over the queen’s duties and allow the colony to persist.