Fire ant facts for kids
Quick facts for kids Fire ant |
|
|---|---|
 |
|
Scientific classification  |
|
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Hymenoptera |
| Family: | Formicidae |
| Subfamily: | Myrmicinae |
| Tribe: | Solenopsidini |
| Genus: | Solenopsis Westwood, 1840 |
| Type species | |
| Solenopsis geminata Fabricius, 1804
|
|
| Diversity | |
| 201 species | |
Fire ants are a group of ants known for their painful, burning sting. They belong to the genus Solenopsis, which includes over 200 different species. Many people call them "ginger ants" or "tropical fire ants" because of their reddish color and strong sting. While some ants bite and spray acid, fire ants use a special stinger to inject venom, which feels like a burn.
Contents
What Do Fire Ants Look Like?
The bodies of adult fire ants, like most insects, have three main parts: the head, the thorax, and the abdomen. They also have three pairs of legs and a pair of antennae. In the United States, invasive fire ants often have a copper-brown head and thorax, with a darker abdomen. Worker ants can be blackish to reddish and vary in size from 2 to 6 millimeters. In a single nest, you can find ants of all these different sizes at the same time.
You can tell Solenopsis ants apart by a few features. They have a two-part waist (called a pedicel) and antennae with 10 segments, ending in a two-segment club. Fire ants use their strong jaws (mandibles) to bite and hold onto things, but their real defense is their stinger. This stinger injects a special alkaloid venom that causes a lot of pain.
How Do Fire Ants Live and Behave?
Fire ant colonies often build large mounds in open areas. They eat young plants, insects, and seeds. They can even attack and kill small animals like lizards. Unlike many other ants that bite and then spray acid, fire ants bite just to get a grip. Then, they sting from their abdomen, injecting a toxic alkaloid venom called solenopsin. For humans, this sting feels like a burning sensation, which is how they got their name. The sting can be very serious for people who are allergic. Fire ants are more aggressive than many native ant species, and they often push other ants out of their homes.
These ants are very tough and can survive difficult conditions. They do not hibernate, but they can handle cold weather, though it can reduce their numbers. Fire ants have also been seen helping certain butterflies. For example, some Lycaenidae and Riodinidae butterfly larvae produce a sugary fluid. Fire ants carry these larvae back to their nest and protect them while feeding on the sweet fluid.
Fire ants usually build their nests in the soil, often in moist places like river banks, pond shores, or watered lawns. Sometimes, their nests are hidden under logs, rocks, or bricks. If there's no cover, they build dome-shaped mounds in open fields or parks. These mounds can be quite tall, sometimes reaching up to 40 centimeters, or even a meter high in some soils. New colonies start with a few queens or just one queen. Even with one queen, a colony can grow to thousands of ants in about a month. Some nests can have many queens (this is called polygynous).
Fire ants are also good at surviving floods. During Hurricane Harvey in Texas in 2017, people saw huge clumps of fire ants, known as rafts, floating on the water. These "rafts" could have as many as 100,000 ants, forming a temporary home until they found dry land. They work together to keep their raft stable in the water. Fire ants are also efficient tunnel diggers, with about 30% of the colony working on tunnels to avoid traffic jams underground.
Fire Ant Reproduction and Life Cycle
Fire ant colonies have different types of ants, each with a special job.
The Queen Ant
The queen is the largest ant in the colony and her main job is to lay eggs. Young, virgin queens have wings and fly to find a mate. After mating, they often break off their wings and start a new colony. A queen can live for up to seven years and lay as many as 1,600 eggs every day! A single colony can grow to have 250,000 worker ants.
Male Ants (Drones)
Male fire ants also have wings and fly to mate with queens during a nuptial flight. After a male has mated with a queen, he is not allowed back into his original colony and will eventually die.
Worker Ants
Worker ants do most of the other jobs in the colony. They come in different sizes, from very small (minima) to larger (major). The larger workers often help break down and store food. Smaller workers handle daily tasks like caring for the eggs, larvae, and pupae (the young ants), cleaning the nest, and finding food.
Fire Ants as Invasive Species
While most fire ant species don't cause problems for people, one species, Solenopsis invicta, is a big problem in many parts of the world. It's often called the red imported fire ant, or RIFA. This ant is an invasive pest in countries like the United States, Australia, China, and Taiwan. It's believed they were accidentally brought to these places in shipping containers.
In Australia, RIFA ants were first found in the Port of Brisbane in 2001. As of September 2025, the main invasion area is about 7,000 square kilometers in South East Queensland, near the border of New South Wales. There have been other smaller outbreaks in different ports and airports across Australia, which have been successfully removed. Experts believe that almost all of Australia could be a suitable home for these ants. The Australian government has spent a lot of money trying to get rid of them, with significant funding agreed for 2023-2027.
In the US, the FDA estimates that billions of dollars are spent each year on medical care, damage, and control efforts in areas where RIFA ants live. They also cause damage to farms and livestock. Millions of people in the southeastern US live in areas with fire ants, and many of them get stung each year. RIFA ants are found in warmer southern states like Florida, Georgia, and Texas.
Interestingly, some lizards in the United States have adapted to the presence of fire ants over about 70 years. They now have longer legs and new behaviors that help them escape from the ants.
While Solenopsis invicta is the most well-known invasive fire ant, other species like Solenopsis geminata are also dangerous and have spread to many tropical countries, causing problems for local communities.
What to Do About a Fire Ant Sting?
Symptoms and Treatment
Fire ant venom is mostly made of oily substances called solenopsins, along with some proteins. Their stings are painful, causing a burning feeling and red bumps. Within a few hours, the sting site usually swells. After 24 to 36 hours, a white blister (pustule) might form. It's important not to scratch these blisters, as they can get infected and might leave scars. If left alone, they usually flatten out in a few days.
Some people can become allergic to fire ant venom. If they get stung again, they might have a very serious allergic reaction called anaphylaxis, which needs immediate medical help. Doctors recommend using adrenaline for such emergencies.
For regular stings, first aid includes external creams and oral medicines. Many over-the-counter creams contain ingredients like aloe vera gel, benzocaine (an anesthetic), diphenhydramine (an antihistamine), or hydrocortisone (a corticosteroid). These can help reduce itching and swelling. Oral antihistamines can also help. If someone experiences severe symptoms like chest pain, nausea, heavy sweating, trouble breathing, serious swelling, or slurred speech after a sting, it's a medical emergency and needs immediate treatment.
Natural Enemies of Fire Ants
Who Hunts Fire Ants?
Fire ants have several natural enemies that help control their populations.
Phorid Flies
Phorid flies are tiny, hump-backed flies. Two species of these flies are known to be parasitoids of the red imported fire ant in South America, where the ants originally came from. These flies lay their eggs in the ant's body. The fly larvae then move to the ant's head and grow by feeding on its tissues. After about two weeks, they cause the ant's head to fall off! The fly then develops inside the detached head and emerges a couple of weeks later. These flies have been introduced to the southern United States to help control fire ant populations there.
Carnivorous Plants
Some plants are also predators of fire ants. The Venus flytrap, which grows naturally in North and South Carolina, catches many ants, including the invasive RIFAs. It lures ants with a sweet sap, and when an ant touches its trigger hairs, the trap quickly closes and digests the insect. Other carnivorous plants, like sundews and various kinds of pitcher plants, also trap many ants.
Other Ants and Fungi
Other ant species can also be enemies of fire ants, especially when new queens are trying to start a colony without worker ants to protect them. Some types of entomopathogenic fungi can also infect and kill fire ants. Scientists are even developing new ways to use these fungi as a natural way to control fire ant pests.
Different Kinds of Fire Ants
The genus Solenopsis has over 200 species. Not all of them are called "fire ants." Many are small, slow-moving ants that can't sting, and these are often called "thief ants." The "true" fire ants are a group of about 20 species that are larger and will sting aggressively if their nest is disturbed. Some of the most studied species include:
- Solenopsis invicta
- Solenopsis richteri
- Solenopsis geminata
- Solenopsis saevissima
- Solenopsis xyloni
See also
In Spanish: Hormiga colorada para niños
- Ant venom
- Ants of medical importance
- Bullet ant
- Bulldog ant
- Red imported fire ants in Australia
