Solenopsis geminata is a midsized, red ant that moves slowly and deliberately. It is a strong recruiter capable of dominating food resources. The polymorphic workers range from small ants with ovoid head to large ants with square shaped heads. The species prefers more open, unshaded habitats. Nests are usually excavated in bare soil and are recognized by the resulting mound of loose earth surrounding them. It is impossible to tell Solenopsis geminata from Solenopsis invicta in the field. Specimens must be collected and examined under a microscope for positive determination.
This video clearly shows the polymorphic size range of the worker caste. There is also a single worker of a Nylanderia species (vaga?) trying to get to the bait.