According to the Orkin Company, though not a native species in North America, the red imported fire ant has become a common nuisance throughout the southern United States, ranging from Florida to California and as far north as Oklahoma and Virginia. The red imported fire ant (Solenopsis invicta) was accidentally brought into the United States in the 1930s via a shipment of cargo. Initially transplanted into Alabama, they have spread and thrived throughout the southern states with the warm climate and lack of predators.
Fire ants favor warm, sunny conditions. They prefer dry fields and avoid shady areas such as woods. Typical mounds can grow up to 61 cm in diameter and 18 cm high. These colonies can contain several hundred thousand ants, including at least one queen.
When attacking, fire ants first use their mandibles to grip their prey, and then inject venom through a stinger. Fire ant stings are painful for most humans and fatal to some: if a victim experiences a severe reaction such as sweating, nausea or excessive itching, emergency medical services should be contacted immediately. Their sting, which includes alkaloid venom, is highly irritating to humans and results in red bumps and white pustules, which can ultimately lead to scarring.
The sensation of a fire ant burn has been described as “stinging” and “intense burning,” and fire ants are known to attack potential threats or prey in large numbers. A fire ant colony may contain 100,000 to 500,000 insects, thus increasing the likelihood that multiple stings will be inflicted. A pest control agency should be contacted in the event of fire ant activity. Professionals can manage lawn infestations while securing homes against indoor invasions. More information can be found at this website: http://www.orkin.com/ants/fire-ant/ .
This year especially, persistent cold snaps in many traditionally mild areas of the U.S. have prompted questions concerning Imported Fire Ant endurance in the frigid winter weather, according to this website: http://www.extension.org/pages/70330/extreme-temperatures-affect-fire-ants . It’s difficult to expose fire ants to lethal temperatures because they move within the mound to avoid temperature extremes. When temperatures drop, fire ants move deeper into the warmer soil below the surface to avoid the cold. However, if the temperatures drop rapidly they may not be able to avoid the cold, especially if wet soil prevents them from moving deeper in the mound. Persistent cold temperatures are required to impact fire ant populations.
Fire ants die quickly when exposed to temperatures in the teens or lower. Cold impacts on fire ant populations are localized. Fire ant mounds located near homes and other heat sinks will be protected from the colder temperatures to some extent. Even if some colonies die, others will survive. Over time, under optimal conditions, population densities will rebound to pre-existing levels or larger.
A drop in visible activity does not always mean a decreased population. On warmer days after the recent cold snap, dead fire ants workers were found on the top of mound indicating some ants had survived to move the dead ants out of the colony. When the weather warms again in the spring, it will be important to continue to scout for mounds. Problems arise when the perceived drop in population causes population management to cease.
For more information about the effects of temperatures on Fire Ants, check out the FAQ questions on eXtension.org at http://www.extension.org/pages/34823/will-a-hard-winter-kill-fire-ants#.UvkDURbinNA .
For most people a single fire ant sting is a ‘mildly painful’ experience that would quickly be forgotten were it not for the ‘mildly irritating’ pustule, according to Mississippi State University Extension Service. Unfortunately, a stinging encounter with fire ants usually involves more than one ant, and each year many people have the experience of being stung by dozens, or even hundreds, of fire ants.
The pain and irritation associated with a single sting is multiplied many fold in such incidents. Most people recover from such encounters with no lasting ill effects, and it is only when such stinging incidents involve many hundreds or thousands of stings that they become truly threatening. But incidents of this magnitude do occasionally occur, usually involving people who are less mobile due to age, accident or infirmity.
Although a few fire ant stings do not constitute a medical emergency for most people, a very small percent of people develop allergic reactions to fire ant venom. These vary in intensity, but in the most extreme cases even a few stings can result in the life-threatening condition known as anaphylaxis. Each year there are cases of human fatalities resulting from fire ant stings, either due to anaphylaxis or to massive numbers of stings occurring on people who are incapacitated.
Given the pain and discomfort that can result from even a few fire ant stings, it is fortunate that fire ants do not normally aggressively seek out and attack human beings. The vast majority of stinging events occur when people inadvertently ‘attack’ the fire ants, usually by unknowingly stepping in, lying in, or otherwise disturbing the mound. The ants perceive this disturbance as a direct attack and the workers quickly react en masse to defend their colony. More info can be found at this site: http://msucares.com/insects/fireants/sting.html .
According to the National Institutes for Health (NIH), home treatment depends on the location of, and reaction to, the sting. Wash the exposed area with plenty of soap and water. Do not use alcohol to wash the area. Wash eyes with plenty of water if any toxin gets in them. For mild stings, place ice (wrapped in a washcloth or other suitable covering) on the bite area for 10 minutes and then off for 10 minutes. Repeat this process. If the patient has circulatory problems, decrease the time to prevent possible damage to the skin.
Some people are very allergic to fire ant venom. If the reaction is severe, seek immediate medical help and call your local emergency number (such as 911) or poison control. Those who have an allergy to insect bites or stings should carry a bee sting kit (which requires a prescription) and become familiar with how to use it in the event of an emergency.
The National Poison Control Center (1-800-222-1222) can be called from anywhere in the United States. This national hotline number will let you talk to experts in poisoning. They will give you further instructions. This is a free and confidential service. All local poison control centers in the United States use this national number. You should call if you have any questions about poisoning or poison prevention. It does NOT need to be an emergency. You can call for any reason, 24 hours a day, 7 days a week.
The health care provider dealing with fire ant bites measures and monitors the patient's vital signs, including temperature, pulse, breathing rate, and blood pressure. The wound will be treated as appropriate. The sooner appropriate treatment is started, the better the outcome. Patients not allergic to fire ants should be completely fine in a few hours to a few days. More details can be found at this website: http://www.nlm.nih.gov/medlineplus/ency/article/002843.htm .
Fire ant bites can be painful, and most people don’t have many after affects other than some localized bumps and brief reactions to them. More than anything, the affected area is a nuisance that goes away after a short time. However, for those individuals who suffer from allergies to fire ant bites, seek medical attention as quickly as possible to avoid any serious health emergencies. And, stock up on fire ant bait from your local home improvement store. Plus, just in case, keep the poison control hotline on speed dial.
Until next time.