The native rat

Lewis and Clark spoke of three rats, the common European house rat, today called the Norway rat (Rattus norvegicus), the native rat of the Atlantic states, today's eastern woodrat (Neotoma floridana), and the rat in the Rocky Mountains with the hairy tail (Neotoma cinerea).  As the eastern woodrat may be found from Florida to Nebraska, and Texas to the Mid-Atlantic states, it is no surprise Lewis appeared to be familiar with the species.  The unexplained thing is that the eastern woodrat, a noticeable forest mammal weighing around 10 oz., was not described for science until 1818. 

For more information about this North American mammal, click here.