Cardiocondyla obscurior

Cardiocondyla obscurior is a small (~1.5 mm) yellow to yellowish brown tropical species of Ants in the tribe Crematogastrini (Formicidae: Myrmicinae). It is a member of the "Cardiocondyla wroughtonii group" with various very similar species, with an assumed origin in Southeast Asia.
Being an accomplished "tramp ant" it has formed populations around the globe, including even in northern Europe. It is polygynous, and often founds new colonies by nest splitting.