The invasive Caribbean crazy ant resembles a few other ant species in its large colony sizes and "crazy" running behavior. Identification is best handled by the Texas A&M Entomology lab.

The tiny crazy ant, known either as the Rasberry crazy ant or the Carribbean crazy ant, is now in the Austin area.  See the story from the Austin American Statesmen, for more information.  I won’t say much about this except to note that this is thought to be a mostly tropical ant, and the general consensus is that it won’t do as well where winters are cold and humidity is low.  Whether it will turn out to be a serious problem in relatively dry Austin, or whether it will establish as far north as Dallas is yet to be seen.

The Austin American Statesman article gives instructions for sending these to an entomologist in College Station for identification.  Also, you can check out the website at Texas A&M for more information on these little gals.