Rats are one of the most damaging pests in the United States. They cause trouble by contaminating food products, nesting and gnawing on structures and by spreading parasites and diseases to humans and domesticated animals. There are two main types of rats that infest structures in the United States, roof rats and Norway rats. Both species of rats are highly adaptable and they can be found in a wide range of residential, agricultural and industrial structures and areas.

How Long Do Rats Live?

Adult rats can live for about 1-3 years. Females can reach breeding age within 2 months but usually start reproducing at around 5-6 months. The gestation period lasts about 21-25 days and a usually produces 6-13 pups (rat babies) Rats can typically produce 5-10 litters per year.

How big are rats?

• Roof rats range in weight from 5-10 ounces
• Roof rats range in length from 10 -12 inches long
• Roof rats are sleek of build
• The tail of a roof rat, pulled over the body, will typically reach the nose

• Norway rats range in weight from 7-18 ounces
• Norway rats range in length from 13-18 inches long
• Norway rats are larger of build and more robust
• The tail of a Norway rat, pulled over the body, will only reach the ears

• Rats have 4 legs
• Rats have short fur
• Rats have tails that vary in length but are generally not hairy
• Rats have beady black eyes
• Rats have two small ears

Myths revealed:

Do rats have bones?

While rats can squeeze their way into very small spaces, they do have bones.

Do rats have bladders?

While rats do frequently urinate, seemingly uncontrollably, they do have bladders.

Norway rats have fur that is dark brownish to black in color, with a paler colored belly.

Norway rat tails are dark on top and paler underneath.

Roof rats have fur that is dark grey to black with a lighter grey belly

Roof rats have uniformly dark tails with a finely scaly texture

Norway rats are spread through just about every state in the US.

Roof rats have a more limited range are most frequently found in coastal areas