The Ants- Most Successful colonisers of the Earth
Homo sapiens are arguably the most intelligent species to have colonised the earth and have the most impact on the ecosystem and evolution. Let’s talk about ant colonies. If we consider the total biomass of all ants on earth it will be comparable to the biomass of all human species. So the title for the most successful colonisers of Earth is still up for debate. This is the reason ants are a key membrane in evolution events and the ecosystem of the earth. In this article, we will look through the lifecycle and colony structure of ants followed by how ants communicate. Lastly, we will discuss how ant colonies act as a superorganism in itself.
Lifecycle of Ants
Ants have a complex life cycle when compared to other insects. The Ant queen who is the Royalty of the ant colony is the only reproductive member who can produce eggs. The queen is the largest ant in the whole colony when compared to other ants.
The ant queen of a particular colony lays millions of eggs throughout her life span, however, these eggs are non-reproductive worker eggs. A queen ant can lay up to 300 million eggs throughout her lifetime. When the colony size reaches a particular number the mother queen decides to lay a different type of eggs.
These eggs are special because the ants that hatch out of them are bigger than normal worker ants. The males are produced only through this specialised way. The female is of two types: reproductive(produced through specialised eggs) and non-reproductive(worker ants).
These special reproductive ants also have wings, the male and the female alike. This is the time when the nuptial flight happens and the male and female winged ants meet at a common breeding ground to mate.
After fertilisation, the male reproductive ants die immediately. The female reproductive ants lose their wings and land on the ground to find a place to dig their nest. However, most of these ants are killed by the predators and only some ants survive. If the female reproductive ant survives she becomes the new queen ant of a new colony and can now take hold of her new dynasty.
After taking a look at the lifecycle of ants let’s see how the colonies of these ants are structured.
After the queen starts laying eggs the new ant colony is established.
The colony is divided into two castes:-
- Reproductive ants
- Non- Reproductive ants
Reproductive ants are produced only after the colony has reached a particular size. The queen lays specialised eggs that produce this caste of ants. This caste includes male and female ants alike. The male members of ant species have only a job which is to reproduce when the winged specialised reproductive females are ready to mate and after they have mated they die. The female members of ants are of two types, one type of female is reproductive and has wings. If they successfully mate they can start their colony and establish their dynasty by being the queen.
The other type of female is non-reproductive. Hence all members of the cast of non-reproductive ants are all females. These females do not reproduce and they are created only for the welfare of the queen. Millions of worker ants are present at a given time which maintains the colony. They perform several jobs. The job that the ant will perform is decided by the already existing older worker ants.
The size of the worker ants depends on nutrition. If they are fed mostly insects they grow bigger and if they are fed mostly seeds their size remains relatively small. The type of nutrition received by worker ants is decided by the existing ant’s members in the colony.
Examples of worker ants
Some examples of worker ants are:-
- Soldier ants: these ants are the biggest and go to war with neighbouring colonies or protect their colonies from attack by predators and other ant colonies.
- Excavator: they are the biggest after soldier ants, these ants excavate tunnels for ant and food movement
- Foragers: These ants are smaller than excavators and look for food by leaving their colony and exploring. A forager ant lives for maybe 1 week but manages to collect food twenty times its biomass.
- Garbage collector: they are the second smallest ants and they collect garbage and clean the ant colony.
- Farmers: they are the smallest ants and they take care of larvae and farm fungus for food.
Communication in Ant colonies
Ideally, it is believed that communication is what gives ants the necessary edge to be the most successful colonisers of earth. Ant communication is a very complex phenomenon. They have very dim hearing and sight hence communication is done through chemicals called pheromones and physical movement. Ant communication has a similar syntax to human communication making their communication extremely effective.
When we see an ant trail the chaotic pattern of a regulated movement can be easily observed. This is done by secretions of pheromones by the Dufour’s gland. The ants secrete this pheromone to convey other ants to follow the trail.
When the ant encounters a food source it leaves a pheromonal trail by the rectal gland. The ant creates the trail from the food source up to the next available worker ant of the colony and starts shaking her head and combines its limbs with the limbs of the other worker ant hence signalling to find the food source.
When ants encounter an enemy which can be a large predator or an attack from an ant colony. It produces a pheromonal trail around the enemy from the sternal gland. It also releases chemicals in the air that relay the battle tactics to other ants. Various chemicals have different instructions for the ants. These instructions can be to be alert, go to the enemy, bite anything in the path or attack enemies. Similar to battle tactics in war by the general to different types of troops.
When an ant colony captures an ant from the other colony they cuff that ant by cuffing their antennae similar to handcuffs that police put on prisoners.
Loyalty and The superorganism
Worker ants are non-reproductive and hence selfless because the workers do not have to produce and care for their offspring; they are not interested in their self-interest. Worker ants have undying loyalty to the queen. If the queen ant dies the worker ants do not make any effort to produce a royal successor who can now lead the colony, instead they all just sit down and do nothing until all the ants in the colony die.
Other animal groups who are cooperative are also competitive (including humans as well). They are concerned about the welfare of the whole group but look out for the self-interest of themself and their offspring. Ants however are different from other animal groups in this regard because they are not concerned for their welfare but only the welfare of the colony. This allows the ants to have colonised all the six continents on earth except Antarctica.
Worker ants’ existence is essentially sacrificial. Hence we consider a new concept called superorganism, meaning that the ant colony is an organism in itself, the reproductive members are like the reproductive structures of the organism and the workers are responsible for other bodily functions like being the brains and the guts, so when the queen dies the organism slowly dies as well.
So the next time you look at ants in your backyard just like you did with your mountain of curiosity when you were a kid, think if this ant is a forager collecting food or maybe a soldier fighting war, who knows maybe you’ll encounter the largest queen ant too. Bring your childhood curiosity back and keep reading at MBD. Hope this article gave you idea about ant colonies.
Check out this incredible video on the same- The Insane Biology of: Ant Colonies – YouTube
This one is totally worth reading- Remarkable Blanket Octopus seen after 21 years – My Biology Dictionary