This trait is responsible for the nickname "trade rat" or "pack rat". In English, the words "pack rat" and hoarder are used for such people. One form of midden analysis examined the size of fecal pellets in pack rat middens. During the excavation, a pack rat fell into the pit and died. A pack rat midden is a debris pile constructed by a woodrat. Instead, it builds small nests in pack rat houses or under dead agaves. The Allegheny woodrat ("Neotoma magister"), is a species of "pack rat" in the genus "Neotoma". A pack rat is a small rodent in the genus "Neotoma". In "Pack Rat&colon; A Metaphoric Phantasy" (1942), rats parody humans, but lack souls. "Rat Pack Rat", as a Sammy Davis impersonator hired to perform at a birthday party.