Rats are rarely found in homes, but can be a problem in garages, sheds and in commercial establishments that serve food. The brown rat or Norway rat may be as large as 18 inches with a 6- to 9-inch hairless tail. Also known as a sewer rat, these rodents are more likely to be seen in landfills, junk yards and scavenging near dumpsters in alleys where they can find food.
The Norway rat will gnaw wiring and can cause severe damage chewing through structures. Despite their large size they can squeeze through gaps as narrow as half an inch. You will rarely see rats, but evidence of their presence is usually droppings or gnaw marks near nesting areas, which will usually be near water and food sources.
Rats carry diseases that can be dangerous to humans and animals. Any sign of infestation should be handled quickly.