Ants are small pests known for their highly organized colonies and remarkable teamwork. One of the more curious behaviours people observe is ants carrying away dead ants. While it might seem strange, this action is important in maintaining the colony’s health and safety. In this article, we’ll explore the reasons behind this behaviour, the processes involved, and what it tells us about ant behaviour.
What Is Necrophoresis?
The act of ants carrying away dead ants is known as necrophoresis. It is a type of cleaning behaviour that helps to keep the colony clean and free from disease. When an ant dies, its body can become a breeding ground for bacteria, fungi, or other harmful organisms. By removing dead ants, the colony reduces the risk of contamination, which is critical for the survival of its members.
Why Is Necrophoresis Important?
Necrophoresis isn’t just a random act—it’s a behaviour that evolved to protect the colony. Ant colonies are made up of hundreds or even thousands of individual ants, and in such a densely populated environment, disease can spread quickly. Dead ants can harbour pathogens, so removing them as quickly as possible is a way to safeguard the rest of the colony. The worker ants tasked with this duty act as a form of sanitation service, ensuring the group’s health.
The Chemical Signal Behind the Behavior
One of the most interesting aspects of necrophoresis is the way ants identify a dead member of the colony. Ants use chemical signals known as pheromones. When an ant dies, its body begins to release certain chemicals, specifically oleic acid, which signals to other ants that it’s time to remove the body. This chemical cue triggers the ants to pick up the dead ant and carry it away to a designated area known as a midden—essentially the colony’s waste dump.
How Do Ants React to Dead Ants?
Ants are constantly touching and sensing their environment through their antennae, which allows them to pick up chemical signals. If an ant detects oleic acid, it immediately recognizes that its fellow ant has died and reacts accordingly. Interestingly, if you apply oleic acid to a live ant, other ants will treat it as though it is dead, attempting to remove it despite its protests!
Ant Middens: The Graveyards of the Colony
Once the dead ant is removed from the central nest area, it is typically taken to a midden, a location that serves as a waste disposal site for the colony. The midden is where ants dispose of not only dead ants but also other waste materials like leftover food or feces. This area is often located far from the nest to ensure that the colony remains free of pathogens and other threats.
Why Don’t Ants Bury Their Dead?
Unlike some animals that bury or consume their dead, ants opt to create a waste pile. This behaviour is linked to their need to manage their environment effectively. Burying the dead would require energy and resources while moving them to a midden is a quick and efficient way to handle the problem.
Ant Social Structure and Division of Labor
The behaviour of carrying dead ants also reveals a lot about how ant colonies operate. Ant societies are built on a highly structured division of labour. Every ant in the colony has a specific role to play, whether it’s foraging for food, defending the nest, or taking care of the queen. Necrophoresis falls to a subset of worker ants, who are responsible for tasks related to maintaining the colony’s cleanliness and overall well-being.
What Does This Say About Ant Intelligence?
Although ants are small and seemingly simple creatures, their behaviour demonstrates a level of collective intelligence. Ants operate through a decentralized system where individual ants follow simple rules, but together, they create complex and efficient systems. Necrophoresis is just one example of how ants solve problems through cooperation and specialized roles within the colony.
What to Do If You Spot Ants Carrying Dead Ants in Your Home
If you notice ants carrying their dead in or around your home, it’s a sign that an ant colony is nearby. While it may be interesting to observe their behaviour, it could also indicate an ant infestation, which might lead to more serious issues like food contamination or structural damage.
Tips for Managing an Ant Infestation:
- Identify the source: Find where the ants are coming from and locate the colony if possible. Ant trails can lead you to the nest.
- Seal entry points: Block any cracks, crevices, or holes that ants could use to enter your home.
- Remove attractants: Clean up food scraps, spills, and any water sources that might be attracting the ants.
- Use baits: Ant baits are an effective way to eliminate the colony by poisoning the workers carrying the poison back to the nest.
- Contact a pest control service: If the infestation is intense, it’s best to contact a professional who can assess the situation and offer targeted treatments.
