Of the eight species of woodrat found in North America, the bushy-tailed is the only one native to Montana. Better known as "pack rats," these rodents are compulsive collectors, and favor shiny objects like broken glass, tinfoil and bottle caps. Pack rats build complex structures called "middens," which provide protection from predators and usually shelter their nests. Built of sticks, bark, rocks, bones, animal droppings, and leaves gathered during nightly forays, middens are solidified by urin