The answer to fire ant nests is that they are a common pest problem, especially in warm climates. Fire ants build mounds in the soil and can be aggressive, delivering painful stings that can cause allergic reactions in some people. The key causes of fire ant nests are availability of food sources, warm temperatures, and suitable soil conditions for their colony to thrive.
Symptoms of a fire ant infestation include the presence of mounds in the yard, seeing the ants themselves, and experiencing painful stings. The best solutions are to use approved insecticides to treat the mounds, remove food sources, and make the environment less suitable for the ants. In some cases, it's best to call a professional pest control technician, especially if the infestation is severe or if you have concerns about safety or effectiveness of DIY methods.