It is a pest in horticulture[6] and one proposed method of control is to introduce the scuttle fly phorid into its habitat.

[11][12] S. saevissima is named so because it is known to be even more vicious than S. invicta the red imported fire ants, which costs the United States millions of dollars per year in agricultural, medical, and traffic-related damage.

Similarly to other species within Solenopsis, it has a conspicuous central hair on the front of its clypeus that extends beyond the outer margin of mandibles.

Differently from most other species in the group, it lacks a well-developed medial clypeal tooth and its propodeum is rounded.

Currently it is believed that nominal S. saevissima actually comprises at least 5 cryptic species (i.e. of identical morphology)[15] that can be separated using chemical characters.

The stable inhabitants of the nest, similar to those of the other fire ants, include one reproductive queen and hundreds to thousands of sterile daughter workers.

The virgin queens must soon leave the nest to establish their own colonies and the drones only live long enough for the mating flight and then they die afterwards.

For S. saevissima, the workers are all sterile female daughters who dedicate their lives to the caring and protection of their future sisters: the broods of the fertile queen (their mother).

In eusociality, the sterile ants often perform specialized tasks to effectively care for the reproductive queen, including group defense and self-sacrifice.

Then it is no surprise that the eusocial workers do give up their reproductive ability to take care of their sisters because, mathematically, they are able to pass on more of their genes in this method.

[18] S. saevissima often displaces the other ant species within the vicinity of its nest because it is omnivorous and opportunistic and prefers abundant food supplies, therefore reducing the resources for others.

If they find a small, single food source, they will attempt to drag it back to the nest.

However the number of workers in the mass forage does stabilize at a certain level because those who are unable to reach the food leave without laying any trails.

In one experiment, adult workers were observed to carry grits coated with a special chemical extract into the nest.

[25] Colony emigration for S. saevissima occurs in a similar manner to mass foraging: communication through chemical signals.

[5] S. saevissima is native to the tropical and warm climate regions of South America, especially eastern Brazil (Pelotas).

[7] It is commonly found in the disturbed areas of grasslands and forest openings due to its workers' nature as excellent recolonizers.

S. saevissima has been mostly restricted in the eastern half of South America, with rare imports to Africa and the Galápagos Islands.

The venoms of fire ants are characterized by a variety of alkaloids known as solenopsins (2-methyl-6-alkylpiperidines) that exhibit necrotic, hemolytic, antibiotic, and toxic properties.

[32][33] Venom from the bite of a sterile female fire ant typically causes painful red bumps with white pustules on the skin of its victim.

First aid includes external treatments of topical steroid cream and oral medicines of antihistamines.