Scientific Name: Rattus norvegicus (Berkenhout)
Color: Gray, brown or black
Size: 10 to 12 inches (8" body plus 4"
The Norway rat is the largest of the commensal rodents. They are
thought to be of Asian origin but are found throughout the United
States and the world. These rats have smaller eyes and ears and
shorter tails than the roof rat.
Rats are excellent climbers and often enter a home in the fall when
outside food sources become scarce. They have poor vision and are
color blind, but their hearing, touch, taste and smell senses are
keen. They are excellent runners, climbers, swimmers and jumpers.
Norway rats will eat almost anything but prefer meat, fish and grains.
Norway rats are primarily nocturnal and live in fields, farm lands
and structures. Rats are often found in woodpiles. These rodents
can gain entry to a home through a hole the size of a quarter (1/2").
They typically nest indoors in basements but may be found in attics.
Rats can chew through wiring, causing fires. They also spread numerous
diseases. Historically, the plague was spred by rats, transmitting
the disease by fleas. Various diseases are associated with the rodents,
including murine typhus, infectious jaundice, rat-bite fever, trichinosis
and food poisoning.
Keep firewood stored well away from the structure. Remove debris
piles. Seal any holes larger than 1/4 inch. Remove moisture and