Solenopsis fugax is close relative to fire ants, but is harmless, for humans at least - workers are ca. 2-3mm long and their stingers are too tiny to penetrate human skin. They are a bit dangerous for other ants, they are called "thief ants" because they live in Formica nests and steal their eggs and larvae. The Formica workers are too big to catch the little thieves in their tiny corridors. However, they can also live as normal, honest ants
