How much do you know about Norway rats? Do you know that Norway rats are brown rats? While Norway rats have black hairs, most of their hairs are brown. This gives them an overall brown coloration. If you see black rats scampering around in your yard, or scaling trees in your yard, they're probably not Norway rats. This is important to know as brown rats and black rats behave differently. Do you know that Norway rats dig burrows in the ground? Yup. They're actually very good diggers, and this can present unique issues if these are the rats you're dealing with on your San Diego County property. Let's take a focused look at Norway rats today and discuss some of the problems you can expect from these brown, digger rats.

rat inside of basement

Foundation Cracks

The first thing you're likely to notice is that these rats will dig holes in your yard. These can be unsightly. But the larger issue is that Norway rats dig underneath foundation slabs and undermine building foundations. This can create structural problems.

Plant Damage

Norway rats love fruits and vegetables and digging rats can dig underneath protective fences to get to these. You're going to need to make sure your fencing goes at least one foot under the ground. Norway rats also damage ornamental plants as they dig in landscaping. If you want to maintain a beautiful yard and beautiful landscaping, you definitely don't need these rats around. 

Damage To Exterior Building Materials

Norway rats have strong incisors. They use these teeth to chew holes in your exterior. This will cause ugly holes to appear. But, once again, there is a larger issue to be concerned about. Exterior holes can allow water into your home. This can lead to wood rot, mold problems, and secondary pest problems.

Damage To Your Belongings

When Norway rats find a way into your home, they're not likely to stop chewing. In storage areas, they chew holes in furniture to create nests in the soft fluffy innards. They'll chew holes in boxes and look through the items inside. As they do this, they'll contaminate these items with their feces and urine.

Damage To Interior Building Materials

Norway rats scrape wallpaper off walls and rip up insulation to gather materials for their nests. They'll also chew holes through baseboards, sheetrock, paneling and other materials to gain access to new areas.

When Norway rats chew on structural wood, they sometimes chew through wires. If they chew through a live wire, it can lead to a house fire. We don't need to tell you how bad that could be.

Food Contamination

Norway rats will look for food in your home, and they are predisposed to chew on cardboard. When they get into your pantry or kitchen cabinets and chew into food packages, they're going to contaminate the contents. This can lead to food poisoning.


There are many diseases associated with rodents. There are many you may already know about, such as salmonella or E. coli. Some you may not know about, such as cowpox virus or trichinosis. There are also mysterious illnesses that can result from contamination. You may experience jaundice, or you might have flu-like symptoms caused by rat-bite fever. In most cases, symptoms of these diseases are mild. But serious illness can result in hospitalization and even death.

Ticks, Fleas, And More

Norway rats don't come into your home alone. They carry parasites in their fur. As they move about inside your home, eggs, larvae, flea dirt, and developing ticks can be littered about in your home. These parasites, having been exposed to rats, could present a health risk to you. Ticks and fleas are associated with many diseases, including the plague.


Norway rats get into wall voids and can cause noises that are annoying. If you hear these noises and act quickly to deal with these rats appropriately, you might want to thank them for making those noises. While it is certainly disturbing to hear rats in your walls, it is worse to deal with the other rat problems listed on this page.

How To Respond To Norway Rats

At the first sign of rat activity, contact HomeShield Pest Control. Norway rats can be very difficult to control and there are many ways you can do it wrong. One example is getting a cat. If you're lucky and you get a cat that will actually kill Norway rats, no cat is able to get all the rats on your property. A cat can't get into wall voids and other places where these rats hide. Let our rodent control professional develop a plan and systematically address all the Norway rats on, and inside, your San Diego County property. Reach out to us today for immediate assistance. We can help!