The only rat free continent in the world is Antarctica. Rats live wherever humans live especially in urban areas. They are most easily distinguished from mice by their size. The most common rat in Wenatchee, Moses Lake, Quincy, Leavenworth and Chelan are the Norway Rats which can grow as large as 16 inches!
Norway rats are poor climbers but they can dig well and often excavate an extensive burrow system. This is one of the ways that they will often find their way into a structure. They can also enter a home through any openings as small as ½ inch!
Like mice they are incredibly reproductive. Female rats can breed up to twelve litters per year with up to 14 pups per litter! They are very social and will live in colonies as large as 60 rats in one location. They like to stay close to their food supply though and will typically try to nest within twenty yards of their food supply. The best way to combat a rat problem is to find and remove their food supply.