Norway rats are characterized by which of the following traits?

Norway rats, also known as brown rats, are indeed characterized by reddish-brown fur, which distinguishes them from other rat species. Their physical appearance includes a relatively small head compared to their body size and a blunt muzzle that gives them a distinctive facial profile. This description accurately captures the key characteristics that help identify Norway rats in various environments.

The other descriptions do not align with the physical traits of Norway rats. For instance, the traits attributed to gray fur and large ears apply more to the roof rat, while black fur and a slender body are characteristics of the black rat. Lastly, a very small, round body does not reflect the robust and somewhat heavier body structure typical of Norway rats. Understanding these specific traits is essential for proper identification and effective pest control measures.