What is a defining characteristic of the Norway Rat?

The defining characteristic of the Norway rat is that it becomes independent within 90 days of birth. This is significant as it highlights the rapid development and adaptability of this species, which is essential for survival in varying environments. The young rats, also known as pups, are weaned around three weeks of age and begin to forage for food and establish their territories relatively quickly. This independence allows them to fend for themselves and contributes to the population's growth and resilience.

In contrast, the other options present information that does not accurately describe the Norway rat. For example, Norway rats cannot fly at all, and their lifestyle is primarily terrestrial, rather than living in trees. Additionally, they have the ability to breed throughout the winter if environmental conditions are favorable, which counters the notion of them ceasing reproduction in colder months. Being aware of these characteristics helps pest control professionals identify and manage Norway rat populations effectively.