Strumigenys membranifera, a small and cryptic predatory ant, is one of many ant species that have taken advantage of human trade to spread around the world. Tucson, Arizona, USA
Strumigenys rostrata Urbana, Illinois, USA
This South American trap-jaw ant species was accidentally imported to North America where it is now widespread- though not particularly conspicuous- in warmer regions. Brackenridge Field Laboratory, Austin, Texas, USA.
