Strumigenys gundlachi and Strumigenys eggersi are tiny predatory ants that feed on minute soil arthropods. Both these closely related New World species were originally described from Caribbean islands (S. gundlachi from Cuba, S. eggersi from St Thomas) and both are known from South and Central America, the West Indies, and peninsular Florida. Recently, exotic Old World populations of S. eggersi were reported from American Samoa and Singapore. I compiled and mapped specimen records for these species to document their known geographic ranges and compare their ecologies. I found S. gundlachi and S. eggersi records from 20 and 41 geographic areas (countries, island groups, major islands, and US states), respectively. These two species have strikingly different habitat preferences. Strumigenys gundlachi is found primarily in intact tropical forest, whereas S. eggersi is found in a wide variety of habitats and is common in highly disturbed environments. The ability to thrive around human disturbance apparently has allowed S. eggersi to spread more widely than S. gundlachi. The original native New World ranges of S. gundlachi and S. eggersi remain uncertain.