A '''rat''' is a small [[rodent]] found on all [[continent]]s except [[Antarctica]]. In the wild, rats are often considered to be [[pest]]s. They may be associated with the transmission of disease. Infected fleas living in the fur of rats are supposed to have spread [[bubonic plague]]. The [[taxonomy|genus]] ''Rattus'' includes over 50 species.
+
A '''rat''' is a medium-sized [[rodent]] found on all [[continent]]s except [[Antarctica]]. In the wild, rats are often considered to be [[pest]]s. They may be associated with the transmission of disease. Infected fleas living in the fur of rats are supposed to have spread [[bubonic plague]]. The [[taxonomy|genus]] ''Rattus'' includes over 50 species.