While the globally distributed urban rats are present in disturbed forest edges and human-adjacent areas, they are not true residents of healthy, deep forest ecosystems. Numerous native North American rodents, commonly referred to as woodrats or packrats, are integral components of these wooded environments. These forest-dwelling species are a distinct group from their invasive counterparts. They possess unique physical traits and behaviors that allow them to thrive far from human settlements.
Distinguishing Native Forest Dwellers from Invasive Species
The rodents most people associate with the term “rat” (Norway and Black rats) belong to the invasive genus Rattus. These species originated in Asia and thrive in human-altered landscapes, relying on the food waste and shelter provided by urban and agricultural settings. They are opportunistic omnivores and rarely venture into the interior of dense, undisturbed forests, preferring the margins where human activity is present.
Native forest dwellers, primarily those in the genus Neotoma, are ecologically distinct from the invasive Rattus species. Neotoma species are true forest residents, having evolved to inhabit a broad range of natural environments, including deciduous forests, coniferous forests, and rocky canyons. A key way to distinguish these groups is by the tail: invasive rats have long, scaly, and nearly hairless tails, while native woodrats possess furry tails that are often bicolored.
Key Native Rat Species Found in Forests
The native species most commonly encountered in North American forests are the woodrats, or packrats, which comprise over 20 species across the continent. These rodents generally possess large, prominent ears, large eyes suitable for their nocturnal habits, and soft fur that varies in color from gray to reddish-brown.
The Bushy-tailed Woodrat, Neotoma cinerea, is one of the most widespread native species, inhabiting western North America from arctic Canada down to Arizona and New Mexico. This species is the largest and most cold-tolerant of the woodrats, distinguished by its long, densely furred tail, which is flattened and squirrel-like in appearance. Bushy-tailed Woodrats are found in boreal and montane forests, often associated with rocky outcrops, cliffs, and talus slopes.
Another prominent species is the Eastern Woodrat, Neotoma floridana, which ranges across the eastern United States and primarily inhabits forested areas, including rocky bluffs and lowland hardwood forests. The Eastern Woodrat has a furry tail that is sharply bicolored, dark on the top surface and white underneath, lacking the bushiness of its western cousin. The Allegheny Woodrat, Neotoma magister, is a closely related species found in the Appalachian Mountains, preferring to live among boulders and in caves within the forest canopy.
Nesting Habits and Diet
Native woodrats are well-known for their complex shelter construction, often serving as the clearest sign of their presence in a forest. These rodents construct large dens called “middens,” which are structures made from sticks, leaves, rocks, and debris. A midden can be built on the ground, in tree canopies, or tucked into rocky crevices; some species construct stick houses that can reach over three feet high.
These structures are multi-chambered residences that include a soft nest for sleeping, separate areas for food storage, and designated latrine sites. Their habit of collecting and hoarding objects, including plant matter and shiny human items, is why they are commonly called packrats. In arid environments, the woodrat’s urine solidifies the midden structure, preserving plant fragments and acting as a valuable record for paleontologists.
The diet of native woodrats is predominantly herbivorous, consisting of a wide array of native forest vegetation. They forage for leaves, shoots, twigs, bark, fruits, nuts, and seeds, which they store within their middens for later consumption. By consuming and caching seeds, the woodrat plays a role in seed dispersal, contributing to the regeneration and overall health of the forest ecosystem.