Tapinoma sessile - queen and worker. Queens are not only larger than workers, their bodies are structured to hold wings (now removed) and flight muscles. Urbana, Illinois, USA

On a sunny day in mid-February, odorous house ants (Tapinoma sessile) move the spring brood up under a sun-warmed rock to speed their development. Urbana, Illinois, USA

Tapinoma sessile is a polygynous ant species. That is, their nests hold multiple egg-laying queens. Urbana, Illinois, USA