Source : WordNet®

pack rat
     n 1: someone who collects things that have been discarded by
          others [syn: {magpie}, {scavenger}]
     2: any of several bushy-tailed rodents of the genus Neotoma of
        western North America; hoards food and other objects [syn:
         {packrat}, {trade rat}, {bushytail woodrat}, {Neotoma
        cinerea}]