A wood rat is popularly called “pack rat” because of its habit of stealing and “packing off” shiny objects, such as buttons, bottle tops or other bright objects with which to decorate its nest.
Sometimes the rat will trade a pebble or something equally useless it is carrying for a more attractive ring or coin. For this reason it is also called a “trade rat.”
The wood rat is native to the Western world. It looks much like the common house rat, but its tall is furry, instead of naked and scaly. Unlike most rats, the wood rat does not live in sewers and garbage dumps.
It makes its home mostly in wooded country and on rocky hillside and builds its nest in a large heap of twigs.
Its home may tower three to four feet high and resemble a badly-made beaver lodge. The pack rat goes out only at night to look for berries and other plant food, or any nice, shiny object it can “pack off” to its nest. – Dick Rogers