Abstract
In the United States. the small subfamily Pseudomyrmicinae is represented by several species which are known to sting severely. Probably the most common species in the southeastern area is Pseudomyrmex pallidus (F. Smith). As part of a program of study on ant venoms in our laboratories, this paper presents a characterization of the venom of this species, a description of its poison apparatus and a study of the reaction of human beings to its sting. In addition, the possible nature of the venoms produced by the Formicidae is discussed.