RAYMOND, Miss. -- Fire ants can be more than unwelcome guests in the home lawn; their stings can be dangerous for children and pets who share play areas with the pests.

Fire ant stings are characterized by sharp localized pain, swelling and intense itchiness that is just a short-lived nuisance for most. A raised red bump appears soon after the sting and soon turns into a sterile pustule that resembles a pimple. However, the ants’ venom can cause severe allergic reactions in some people and pets.

“Fire ant venom isn’t toxic, and a sting or two by a few ants is usually not a big deal,” said Jerome Goddard, medical and veterinary entomology specialist with the Mississippi State University Extension Service. “But a small child or pet that inadvertently steps in a mound and doesn’t realize it right away or doesn’t know what to do could get many stings. If that child or pet is allergic to the venom, just one sting could be very bad.”

For both people and pets, anaphylactic reactions are the most dangerous. Anaphylaxis is a severe allergic reaction characterized by hives, swelling and spasms of the airway, and low blood pressure from the collapse of blood vessels. If not treated, these reactions can be fatal. Secondary infections also can develop if the child or pet scratches the bite and breaks the skin.

“While it is rare, secondary infections can progress to sepsis, or blood poisoning, if they aren’t treated at the first sign,” said Dr. Jeb Cade, assistant clinical professor in the MSU College of Veterinary Medicine Department of Clinical Science.

Extreme inflammation caused by a sting can compromise blood flow to an extremity. The body’s immune system usually mediates this reaction, but if this happens to a pet, owners should monitor the condition and seek medical attention if swelling does not subside, Cade said.

Homeowners can reduce the chances that children and pets will come into contact with fire ants by implementing a treatment plan for their yards.

“There are effective treatments to control fire ants that are relatively inexpensive, easy to apply, and safe for people and pets when used according to the label directions,” said Blake Layton, MSU Extension entomology specialist and professor in the Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology.

Control products for use on home lawns must state how long people and pets should avoid the treated area, a time period known as the re-entry interval or REI. Most home lawn pesticides have short re-entry intervals, but others may require 24, 48 or 72 hours before the area can be entered again, Layton said.

“There really are not many of these long REI products anymore, especially among those we use for fire ants,” he said. “For example, the label on Amdro Fire Ant Bait says people and pets can use the area immediately after a treatment has been applied. But there is no reason a concerned homeowner can’t take extra precautions, such as adding a day or two to the REI following pesticide use.”

Insect growth regulators are an alternative to fire ant baits. These products take more time to work but are generally safer for pets, Cade said.

“Most fire ant baits have low mammalian toxicity when used as the label directs,” Cade said. “These products are designed to be broadcast over the entire yard and taken back to the mound by workers and fed to the queen. But the biggest problem with these products is that the sugar, corn and oil used to make them attractive to ants also make them attractive to our pets.”

For this reason, homeowners should store pesticides in an area that children and pets cannot access.

“The greatest health risk to children and pets related to pesticides is from accidental poisoning due to ingestion or exposure to the concentrated product,” Layton said.

Fire ant mounds can number between 50 and more than 200 per acre in untreated areas. Such infestation pose more of a risk to people and pets than the products recommended to control them, as long as those products are used and stored properly, Layton said.

“Gasoline provides a good analogy,” Layton said. “Gasoline is a highly flammable product that may be fatal if swallowed or aspirated and is a suspected carcinogen, but most homeowners store gasoline on their property and are able to use it safely in lawn mowers and other gas-powered equipment -- as long as they take appropriate precautions when storing and handling it.”

For more information about safe control of fire ants in the home lawn, refer to MSU Extension Publication 2429, “Control Fire Ants in Your Yard.”