In fact, it is unusual to find Norway rats above the first floor.

The main conservation issue is the large population of Norway rats on the island.

Norway rats were accidentally introduced to the island in the 1980s.

Norway rats are born after a gestation of only 22 days.

It is one of the largest islands from which Norway rats have been eradicated.

Despite this, this species' common name of "Norway rat" is still in use today.

The mammalogists noted that they did not find any Norway rats or house mice.

His hair was about the color of a Norway rat and parted just above his left ear.

Not when the flourishing species is the Norway rat.

The subject of his thesis was the 24-hour rhythms of the Norway rat.