Ant colonies exhibit various behaviors to ensure survival and adopt different strategies to survive threatening and unfavorable environmental conditions. Polydomy in ants is a natural behavior among a few species when their colonies spread on a larger surface area.
What is a Polydomous Ant Colony? Polydomous ant colony refers to a colony of ants making multiple nests at a small distance that are socially connected. It allows them to access diverse food sources, reduce competition, regulate nest population, expand colonies, and ensure minimum traffic.
Monodomy and Polydomy are observed in different species of ants, but monodomous ant colonies are more common in which they build only one nest and live there.
The distance between the old and new nests ranges from a few meters to several meters, as they can be almost 5 to 7 meters apart or spread up to 30 to 35 meters.
What is the meaning of polydomous ant colony?
The term ‘Polydomous’ is derived from two different words: poly means multiple or more than one, while domous means home.
Polydomous means multiple nests, and this term is commonly used for social insects when they occupy more than one location for nests and live there simultaneously.
It means a colony of ants known to inhabit more than one nest. The total population divides, and a small proportion moves to a new location to make a new nest.
These nests are only separated by a small distance while remaining connected socially. The workers keep moving from one nest to another to share their food and water resources and ensure survival.
Moreover, they simultaneously occupy and maintain multiple nests and coordinate to overcome environmental challenges and predation threats.
Argentine ants are known to make a socially connected polydomous colony. Each of their nests contains a queen and a large number of workers.
Their colonies have almost thousand to hundred thousand members, depending on the season of year and the environmental conditions.
So, they form a supercolony covering a surface area of almost 3000 miles when multiple nests are at a small distance.
Why do ants have polydomous colonies?
Polydomous colonies offer many benefits to ants as they can cover a large surface area of their territories and access food sources at different locations.
Some other benefits include reducing the saturation of nests by thousands of nest members and lesser competition among them.
Access diverse food sources
They can exploit diverse food resources by making nests at different locations, as they can cover more foraging areas and stay connected to their nests.
They slowly move to different locations and reach the new food sources close to their new nests. This way, a variety of food is available to them when they explore new habitats.
Moreover, the worker ants make a new nest when no food is available to feed a large colony. They carry larvae and eggs and move to places with plenty of food.
Accordingly, they get a different type of food in a new habitat and adapt to explore and eat the food resources. So, these colonies can survive food shortages by making new nests.
The formation of multiple interconnected nests helps avoid the risk of competition among colony members. The foragers collect food from different areas, as each colony has its own foraging space.
The spatial separation decreases competition for resources like food and space, as the colony separates by budding and half of their members move to a new location.
Each nest may have a different type of food depending on the availability of food type in their habitat. One of the nests of polydomous ant colony feeds on nectar, while others hunt insects.
Additionally, the intraspecific competition reduces between foragers when fewer food-collecting worker ants are present in a specific area.
So, it provides an opportunity to forage in different directions and reduces interference in activities that arise when many foragers approach a single food source or live in the same place.
Effective survival strategy
It is an effective strategy for long-term survival by a few species of ants because dividing the colony members into multiple nests reduces the risk of death of an entire colony.
Bad weather and heavy rain can cause damage to one nest if its habitat is different, but the other remains safe due to its presence at a distance from the first one.
This way, all of their population is not prone to damage simultaneously, as a few of their nests get flooded by rainwater while others remain dry.
In the same way, different types of predators are present at various locations. Hence, the risk of predator attack at one colony poses a survival threat to it only, and others survive.
Minimum traffic within nests
Mainly, these consist of workers who are always busy doing tasks and move in and out of the nest several times.
The presence of thousands of worker ants in one colony increases traffic when they bump into each other while moving out of the nest or coming inside it.
Accordingly, a few of them move to a different location to reduce the traffic flow as increased bumping leads to disruption in activities and minor injuries sometimes.
Regulation of population
They can efficiently regulate the nest population by moving to a new nest that helps accommodate the extra population.
The presence of thousands of ants in a limited space causes disturbance in activities and affects the quality of nests.
Accordingly, some workers build a new underground nest or a mound above the ground after finding a suitable place at some distance from their old nests.
However, they remain connected with their fellows and visit their old homes several times when they need help or food.
Flexibility in colony expansion
Making multiple nests benefits the ant colony because they can expand their size and establish dominance on a larger surface area.
This way, they become a dominant species in a particular habitat when more than one colony is present at a small distance from each other.
The carpenter ants (Camponotus leydigi) also inhabit multiple locations and build nests that are almost 25 to 30 meters apart, meaning they can cover several meters in a territory.
What type of ants have polydomous colonies?
These are found in some ant species that have adapted this survival strategy and make multiple nests to distribute their population in different locations.
The largest number of nests are found in the Argentine ant colonies, known to cover a surface area of a few thousand miles by interconnecting their separate nests.
In addition, the wood ants, mainly Formica rufa and Holartic formica, also have polydomous colonies, while some of their species exhibit monodomous behavior.
The odorous house ants also exhibit this behavior and make satellite nests at some distance from the old one, and all of these colonies remain functional simultaneously.
Furthermore, pharaoh ants have polydomous colonies and live in multiple locations by finding new shelters in favorable places.