When it comes to stinging insect allergies, many people are familiar with bee allergies. Ants are another insect that can cause serious reactions, including anaphylaxis. With red imported fire ants now becoming a problematic pest in many countries including Australia, it’s important to be aware of allergy to red imported fire ants. Find out more about these aggressive ants, how to avoid stings and what to do if you have symptoms of an allergic reaction.
What are Red Imported Fire Ants?
Red imported fire ants (Solenopsis invicta) are a species of ant originating in South America. These ants have now spread to other parts of the world, including the US and Australia (especially Southern Queensland).
These highly aggressive ants are a copper brown colour, with a darker abdomen. Fire ants vary in size from 2-6mm in length. Nests usually contain ants of different sizes.
Unlike some other ant species, it can be harder to recognise where red imported fire ants are nesting. Their nests look like patches of loose soil and don’t have obvious entry holes. Red fire ant nests are often located in lawns and gardens, near the edges of paths or near a source of water like a tap or dam. If you think you have located a fire ant nest, don’t touch it. Gently poke the mound of soil with a long stick to see if there are ants present.
Biosecurity Queensland has a very informative video about how to identify fire ants and their nests.
One of the reasons red imported fire ants are such a concern is that they are highly adaptable to different environments. They are also very mobile and can fly up 5km (over 3 miles). Other ways they spread are by travelling over or underground, or riding on vehicles, cargo or in plant material. Fire ants even build rafts to travel over water after rain or flooding. It’s easy to see why they are considered one of the worst invasive species in the word.
Are Red Imported Fire Ants dangerous?
Red imported fire ants are highly aggressive ants and have a very painful sting. These ants don’t actually bite. They grip on with their pincers and then sting with their tail, injecting venom into the skin. The ants act together to defend their territory, so it is common to be stung by more than one ant at once. Red imported fire ants can also sting repeatedly.
According to a Western Australian Department of Health factsheet, red fire ant sting symptoms can last up to an hour and can include:
- a severe burning sensation;
- “fiery” pain;
- redness; and
Some people develop small blisters or pustules on the skin after fire ant stings. Blisters can last up to a day or two after being stung. Broken blisters may become infected.
First aid for red imported fire any stings includes applying a cold compress to relieve swelling and pain and washing the skin with soap and water. If you develop blisters or pustules after being stung, monitor for redness and infection and seek medical advice if concerned.
For most people the stings result in painful symptoms, but in some people can experience serious allergic reactions to red fire ant stings.
Symptoms of an allergic reaction to red fire ants
While people will experience pain and a localised reaction to red imported fire ant stings, others will experience allergy symptoms. Mild or moderate allergic reaction symptoms include swollen lips, face or eyes or itchy hives on the skin. Mild symptoms usually resolve with antihistamines.
A severe reaction to red imported fire ants (known as anaphylaxis) may start with mild or moderate symptoms and get worse, or it may come on very suddenly.
The Australian Society of Clinical Immunology and Allergy (ASCIA) submission to the recent Parliamentary Inquiry that stings from red imported fire ants are 3 times more likely to cause a serious allergic reaction (anaphylaxis) than a honey bee sting.
Symptoms of a severe reaction include:
- Difficulty/noisy breathing;
- Swollen tongue;
- Swelling or tightness in the throat;
- Difficulty talking and/or a hoarse voice.
- Wheeze or persistent cough;
- Abdominal pain and vomiting;
- Loss of consciousness and/or collapse;
- Pale and floppy (in young children).
It’s important to note that vomiting is usually regarded as moderate symptom of an allergic reaction to foods, but for insect stings it is considered a severe symptom.
First Aid for Anaphylaxis
In the case of a severe reaction, seek emergency medical help as soon as possible. If someone has a known allergy to fire ants, locate and follow their anaphylaxis management plan and use their EpiPen or other autoinjector as directed.
For unexpected reactions, follow the steps on ASCIA’s first aid plan for anaphylaxis.
Lay the person flat (or allow them to sit up if breathing is difficult). Administer an epinephrine autoinjector such as EpiPen or Anapen if one is available. Do not allow them to stand or walk while waiting for medical assistance.
How to avoid fire ant stings
If you like to garden, go bush walking or work outdoors in areas where red imported fire ants are prevalent, there are some practical steps you can take. It is a good idea to wear long sleeved shirts, long pants and closed in shoes. For extra protection wear boots and tuck your pants in to close off any gaps. When gardening, make sure you wear gloves. Keep an eye out for ants and their nests when mowing the lawn and watch where you stand (or sit!). Move away from areas where fire ants are active.
Protective clothing can help, but not eliminate risk altogether. If you know you have an allergy to ants you should make sure that you carry your EpiPens and anaphylaxis plan with you and always have a way of contacting someone in an emergency (mobile phone or other communication in remote areas).
Finally, nests on your property should be eradicated. You may want to engage a pest control expert to do this. In Australia, red imported fire ant nests should be reported to the National Fire Ant Eradication Program.
People who have experienced an allergic reaction to red fire ant stings should see an allergist to discuss how to manage their allergy. If you live in the United States, immunotherapy (“allergy shots”) may be an available treatment option for desensitisation.
Unlike treatment for bee sting allergy and jack jumper any allergy, there is not yet any desensitisation treatment available for red imported fire ants in Australia. People with red imported fire ant allergy need to be careful to avoid stings and carry their adrenaline autoinjectors with them at all times.
Senate Enquiry into Red Imported Fire Ants
At the time of writing the Australian Government is conducting a Senate Inquiry into the spread of red imported fire ants in Australia.
In its submission to the inquiry, Australia’s peak allergy body ASCIA called for strong efforts to eradicate outbreaks of imported red fire ants in Australia. ASCIA also recommends education to increase public awareness of these ants, how to avoid stings and first aid treatment.
More about red imported fire ants and insect allergies
If you have been diagnosed with a red imported fire ant allergy and have been prescribed an EpiPen, you can find some helpful tips for looking after your autoinjector in our guide to making friends with your EpiPen. You might also like to read about difference between EpiPen and Anapen, the two difference autoinjectors available in Australia.
Find out more about red imported fire ants and allergic reactions to them from these helpful resources we’ve referred to in our post:
- Australian Government, Outbreak, Animal and Plant Pests and Diseases, Red Imported Fire Ant
- Government of Western Australia, Department of Health. First Aid for Fire Ant Stings
- 1Australian Society of Clinical Immunology and Allergy, Response to the Parliamentary Inquiry into Red Imported Fire Ants in Australia, 1 December 2023
- UpToDate, Imported Fire Ants: Beyond The Basics
*Disclaimer: Allergy Spot does not provide medical advice. You should always consult a suitably qualified medical practitioner in respect of your own medical conditions, symptoms or concerns. See our Website Terms for more details.