Definitions for "pack rat"
Any of several bushy-tailed rodents of the genus Neotoma of western North America, especially Neotoma cinerea, which hoard food and other objects in their nests.
( Neotoma cinerea) AKA Wood rat. A bushy-tailed rodent that looks sort of like a chinchilla. They are very good at finding ways into buildings and they are known for collecting shiny objects. You can see one in this picture.
someone who collects things that have been discarded by others
A person who habitually saves items, even those unlikely to be useful.