Lookalikes
for Norway Rat
The main look-alike is the roof rat, which is sleeker and a strong climber; its tail is longer than its head and body combined, while the Norway rat's tail is shorter than its body. Where both share a building, Norway rats stay in basements and ground floors and roof rats take the attic and upper levels. A house mouse is far smaller and easy to tell from an adult rat by size. Source: https://ipm.ucanr.edu/home-and-landscape/rats/pest-notes/