Dorymyrmex reginicula (at left), a socially parasitic species, is harassed by a worker of its host Dorymyrmex elegans. Workers of the two species coexist in a single nest for a period after the parasite queen has assumed reproduction and before the last remaining host workers die off. The transition period is not entirely smooth, as evidenced by this aggressive interaction. Archbold Biological Station, Florida, USA
Among the oddest of all ants is the tiny Solenopsis phoretica, a presumably parasitic species whose females ride piggyback on Pheidole queens. Nearly nothing is known about its biology, having only been collected twice. Austin, Texas, USA.
