A Norway rat nest site away from its home; rats may have several. Their home range can be up to how many acres when including these secondary nest sites?

• A. 5
• B. 10
• C. 15
• D. 20

Answer: (D)

When thinking about a Norway rat’s home range, include all the areas they use for shelter and foraging, not just a single nest. If a nest is located away from the home base, rats can maintain several nests and move among them, extending the overall area they cover. In situations with multiple secondary nests, that expanded network can reach around 20 acres. This means control efforts should span a broad zone that could include up to roughly 20 acres, rather than focusing on a single site. Smaller ranges underestimate the space a population may actively use when multiple nests are involved, so planning for up to 20 acres helps ensure all harborage and food sources are addressed.