How Do Parasitic Ant Queens Take Over Colonies: The Chemical Trick That Makes Workers Kill Their Own Queen

An ant colony is a very cooperative society. Thousands of ants march in line, collect food, defend their nest, and take care of their queen. Everything inside that nest is based on order, recognition, and trust. Worker ants heavily rely on chemicals to identify friend or foe.

But in some ant colonies, this system is turned against them.

Scientists have just discovered a horrifying trick that some parasitic ant queens are using against their hosts. Instead of building their own nest, these queens infiltrate an existing nest and gradually take over control of it. But the most shocking thing is how they do it: they trick worker ants into attacking their own queen using chemicals.


Observations of this behavior have been discussed in reports covered by ScienceAlert and other science outlets examining parasitic ant interactions. What scientists saw on camera was unsettling. A foreign queen entered a colony, and within a short time, the workers began attacking the queen they had protected their entire lives.

The change was not random. It was caused by chemistry.

Chemical Camouflage Lets the Parasitic Queen Enter the Colony

The first step for an invading queen is to enter the nest undetected by the colony. Ant colonies are extremely defensive. They can detect an intruder quickly by their sense of smell.

The queens have devised a way to evade detection by their host colony. This is done by what is called chemical camouflage. The queens do not have their own unique smell. Instead, they acquire the smell of their host colony. To do this, they touch their workers to acquire their smell.

Research discussed in the report titled “Why Some Ant Colonies Get Tricked Into Killing Their Own Queens,” covered by NPR, explains that ants rely on chemical recognition systems to identify nest members. Each colony carries its own unique scent signature. If a stranger smells wrong, workers immediately attack.

The parasitic queen avoids that response by blending in first.

Once her scent closely matches the colony, the workers treat her as if she belongs. That brief moment of acceptance gives the parasite a chance to carry out the next step of her takeover.

Formic Acid Turns the Colony Against Its Own Queen

After entering the colony, the parasitic queen approaches the resident queen. What happens next reveals just how powerful chemical communication is in ant societies.

Scientists observed that the parasitic queen releases a small amount of abdominal fluid onto the host queen. Researchers suspect the fluid contains formic acid, a chemical many ants use as a defensive weapon.

According to “The Parasitic Ant Who Makes Workers Kill Their Own Queen,” published by National Tribune, this chemical disrupts the queen’s natural scent. Her own workers can no longer recognize her correctly.

The result is dramatic.

Workers suddenly treat their queen as if she were an enemy intruder. Instead of protecting her, they attack. In many recorded cases, the colony ends up killing its own queen.

Researchers studying these events say the behavior shows how fragile ant communication can be when scent signals are manipulated.



A Colony Taken Over From the Inside

Once the original queen is gone, the parasitic queen moves quickly. She begins laying her own eggs while the worker ants continue their usual duties.

The workers feed the larvae, protect them, and raise them just as they would their original queen’s offspring. Over time, the colony slowly shifts from producing its original species to producing the parasitic one.

Reports discussed in Earth.com and ScienceAlert note that this strategy represents a remarkable form of biological manipulation. Instead of fighting an entire colony directly, the parasitic queen turns the colony’s own instincts against itself.

This process is being studied by scientists as part of the evolutionary arms race that is always going on in social insects. The parasites keep coming up with new ways to deceive chemical communication, and the hosts just keep getting more perceptive at detecting them. The study is a reminder that even the most well-organized organizations in nature can have communication that is very fragile. Lurking just beneath the surface, a subtle chemical shift can turn loyal workers into enemies and rewrite the future of an entire colony from the inside.