"Nepenthes rajah" traps vertebrates and even small mammals, with drowned rats having been observed in the pitcher-shaped traps. It is one of only three "Nepenthes" species documented as having caught mammalian prey in the wild, the others being "N. rafflesiana" and "N. attenboroughii". "N. rajah" is also known to occasionally trap small vertebrates such as frogs, lizards and even birds, although these cases probably involve sick animals and certainly do not represent the norm. Insects, and particularly ants, comprise the staple prey in both aerial and terrestrial pitchers.