The number of queens in an ant colony varies from species to species. In most cases, ant colonies tend to only have only one egg-laying queen. However, some ant colonies may also have multiple or even no queens at all.
In this article we’ll dig deeper into how many queens are in an ant colony as we discuss examples of how different colonies are structured.
Before everything else, let’s first define what we refer to as the egg-laying queens. As the name would imply, these queens are those that lay eggs. These are mated queens that have filled their spermatheca with sperm and are taking responsibility for the colony’s reproductive load.
They’re not to be confused with virgin queens that may also be in the colony at the same time. These virgin queens are produced by the egg-laying queens when the colony reaches maturity and is ready to expand. Their goal is to reproduce and establish new colonies through either the nuptial flight or budding.
When looking into how many queens are in an ant colony, we count only the egg-laying queens, as the presence of virgin queens doesn’t necessarily indicate how a colony is structured queen-wise. These virgin queens are simply awaiting for their time to mate and oftentimes will leave the nest to start colonies of their own.
Monogynous Ant Colonies
Monogynous ant colonies are those with only one egg-laying queen. Alongside this queen are thousands of female workers, all of which have given up their rights to reproduce to instead serve the queen by feeding her and taking care of her brood.
This type of colony structure is found in most ant species and is generally associated with winged reproductive ants which mate on the wing, disperse, and establish independent colonies.
That said, monogynous ant colonies can be either primary, wherein the single egg-laying queen is also the foundress, or secondary in which multiple queens start a colony together but eventually end up with one dominant queen which either kills or pushes out the extra queens.
Polygynous Ant Colonies
Polygynous ant colonies on the other hand, are those that have multiple egg-laying queens. This could mean two queens or sometimes even millions such as in the case of the Formica yessensis. Other polygynous ants include certain species from the Ponerinae, Myrmeciinae, Myrmicinae, Dolichoderinae, and Formicinae genera.
Inverse to monogyny, polygynous colonies can be primary in which multiple queens start the colony together or secondary wherein the colony is started by a single queen and other queens are added later by adoption of fusion with other colonies.
Also, unlike monogynous species which generally mate on the wing, some polygynous reproductive ants are flightless and simply opt to mate near their natal nests. From there the queens may either disperse or return back to their natal nests depending on their ability to fly.
Lastly, in polygynous species, new colonies are typically created through budding wherein a queen and a group of workers depart from their natal colonies to start a new colony elsewhere.
Oligogyny is a special type of polygyny wherein multiple queens occupy the same nest but remain apart from each other. This type of colony is characterized by the tolerance of workers towards multiple queens but also the intolerance of queens among each other.
Monogyny And Polygyny In One Species
It’s possible for one ant species to have either monogynous or polygynous colonies. Certain species like fire and sugar ants may have one or multiple queens depending on environmental pressures.
When feasible, these species participate in mating and dispersal flights which allow them to colonize new areas. In doing so, they tap into new resources and prevent competition over such resources with their maternal colonies.
Polygyny on the other hand, is preferred when the cost of independent colony founding is high such as when there is an abundance of predators, undesirable climate, or a lack of suitable nesting sites. Due to these factors, queens would prefer to be adopted by their maternal colonies instead of starting one of their own.
Queenless Ant Colonies
In most ant species the absence of a queen may lead to the death of the colony. Yet for some ants, being queenless is simply just another day at the office.
The colonies of certain species such as those of the queenless ant Diacamma rugosum, completely lack the queen caste. Instead of relying on queens, the reproductive responsibility in these colonies lie on workers called gamergates.
These gamergates are special workers which are born fertile. They have functional spermatheca and can reproduce sexually. Like queens, they can also use sperm selectively to produce either male or female eggs.
That said, just because all workers are fertile doesn’t mean that all of them get to reproduce. There exists a social hierarchy even in queenless ants. One dominant gamergate will take care of all reproductive responsibility while the rest are rendered infertile and under control of this dominant gamergate. This one worker ant has essentially elevated herself to queen-like status.
What Happens When The Queen Ant Dies?
As mentioned, the death of the queen may mean the death of the colony itself. Without the queen, the production of new workers cease and the colony eventually dies off as the older workers reach the end of their lifespans.
That said, there are of course exceptions such as the case of queenless ants. Also, more and more studies have found queen replacement to be a common occurrence in both monogynous and polygynous ant colonies.
How Does An Ant Become Queen?
Ants don’t necessarily become queens in a sense that an ant may somehow elevate its status. Instead queen ants are queens from birth. They’re produced through fertilized eggs, the same eggs that sterile worker ants hatch out off. They are however fed more as larvae, allowing them to morph into bigger, and in a lot of cases, winged reproductive ants capable of flight.
What Do Queen Ants Do?
In most ant species, queens are typically the only ones which can mate and reproduce. Meaning, they’re also, in most cases, the only ones capable of laying eggs which then allows them to start or grow colonies.
The queen count in a colony may vary between species. Most colonies are monogynous and have only one egg-laying queen. There are also those that are polygynous which have two or more queens in a single colony and even queenless colonies wherein specialized workers called gamergates are fertile capable of taking reproductive responsibility.