The Florida harvester ant Pogonomyrmex badius is the only North American pogo found east of the Mississippi, and the only species that is polymorphic in the worker caste. The individual on the right is a major worker whose enlarged head holds muscles useful for milling seeds. Archbold Biological Station, Florida, USA
Major and minor workers of Solenopsis aurea, a native North American desert fire ant. Bandera County, Texas, USA. Specimen voucher UTIC00210255 .
Solenopsis geminata is a seed harvesting ant, and major workers have massive heads for powering the blunt seed-milling mandibles. Durban, South Africa
