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Roof Rats

Summary: Roof rats can be a persistent pest requiring a lot of detailed exclusion work to keep them out of structures. This article will provide some good tips on how to fight Roof rat invasions.

Roof rats (Rattus rattus Linnaeus) have made their way into and around houses since time began. Its name is derived from the way it prefers to enter properties via the roof area. In earlier times Roof rats arrived in the U.S. from Europe and Southeast Asia by ships, so it is also known as a Ship rat. Yet another name for the Roof rat is the Black rat because one of its sub-species is black, except for its gray belly.


Found in many parts of the United States, the Roof rat nests in high places, both outside and inside. However, as its population expands it may extend its nesting area to include locations closer to the ground like ground floor levels inside and outside of buildings and piles of various materials.

The Roof rat lives mostly in warmer climates of the United States in the Southeast, some Gulf States as well as the Pacific Coast states. It is even found as far west as Hawaii.

To identify a Roof rat, as opposed to its near relative, the Norway rat, look for a scaly, hairless tail that is longer than their 6-8 inch black. Body fur will be brown or gray with lighter gray, brown or white bellies. They weigh around 5 to 8 ounces, whereas the Norway rat is larger, tipping the scales at as much as 19 to 21 ounces.

Like the Norway rat, Roof rats have a spring and summer breeding season with litters 4 to 6 times per year bearing, on average, 4 to 6 pups and gestation periods of approximately 21 to 23 days. The average life span is around one year.

Roof rats may be heard moving around in the attic. It is possible to locate them by discovering their gnawing damages to utility wire insulation or plastic items inside the house. Of course, rodent droppings are also a giveaway. They are active mostly in the cooler fall and winter months.


Although the time old tale is that rats like to dine on cheese, the fact is that Roof rats eat whatever is available and convenient including vegetation, nuts and fruits in their natural outside environment. Once inside a home, such items as pet foods, cereal products and other food items can be found on its dining menu.

Like most rats, the Roof rat usually stays close to its nest when out hunting for food, usually within around 200 feet or so. Because its vision is one of its less developed senses, Roof rats travel closely along walls at night by using its whiskers, body guard hairs and nose to touch and smell its way around in its efforts to locate its preferred food.

So, how best are Roof rats prevented from entering in the first place, then controlled once in the house?

  • Prune and remove vines, trees and other vegetation that allow access to and from roofs and attics.
  • Place and maintain obstacle guards on utility lines and fences where lines attach to or run nearby your residence.
  • Repair cracks or other openings that make it possible for rats to get in.
  • Trap rodents with various types of traps.
  • Bait with rodenticide baits as specified by the label instructions and conditions of use.

Add to that a determined and persistent practice of locating, altering and eradicating rodent nesting to discourage them from living inside or nearby your house.

I do not recommend shooting or relying upon predators such as cats and owls. Nor do I recommend the use of glue boards, tracking powders or fumigants since roof rats seldom burrow. When all else fails, call in the pros.


Valerie Lindow
23 Jun 2009, 17:26
Can you recommend an obstacle guard for our utility lines?

Thank you
Britton Miles
16 May 2010, 21:26
1. What do you do about soffits? Is there a way to stop their accessing the attic, or in our case flat roof, through the soffits?

2. What is the name of the "line-guard" that you use on electrical lines? Would electricians carry them or would I have to order them myself?

Would you give me the name of an internet vendor if I can't find a line guard locally?
Debbie Mays
29 Aug 2010, 22:43
What do I do to get rid of a roof rat that has entered my garage atic by bending the soffit at the top of my roof
Ask the Exterminator
30 Aug 2010, 10:16
Buy a live trap and bait it with sunflower seeds. You can buy the trap at html
Rich bichette
13 Sep 2010, 15:36
What is the name of the "line-guard" that you use on electrical lines? Would electricians carry them or would I have to order them myself?

Would you give me the name of an internet vendor if I can't find a line guard locally?
Ask the Exterminator
16 Sep 2010, 11:30
Try this site:
31 Jan 2011, 02:35
How do you get rid of dead rat smell? I think it died in my ceiling or walls but there is no pratical way of finding the dead thing. And what fogger do you recommend to kill any bugs or worms that might crawl out of it's dead body? thanks.
Ask the Exterminator
31 Jan 2011, 09:36
BacAzap ( ) is the product I recommend for getting rid of dead animal smells. If you cannot find the dead animal you might want to use Nuvan ProStrips
( ) to kill insects in the attic. I have provided the links to each product.

31 Jan 2011, 16:52
Thanks. By the way, how long does the stink last?
31 Jan 2011, 18:08
Sorry one more question. Like I said in my last question, there is no way to get into the roof to find the dead rat, but I saw some ads from some company saying that they can find it with high tech cameras. Have you heard of such a thing? Do you have any suggestions on how to find it? Or what would you suggest? Thanks for any help you can provide.
Ask the Exterminator
01 Feb 2011, 10:09
If you wish to have a conversation you must follow the directions in red.
29 Aug 2013, 01:08
To find a dead rat follow the flies and where the small is strongest. get a small rake from Kmart and poke around DO NOT USE YOUR HANDS!
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