With rats its a little different then with the other 2 species we raise. Rats don't have breeds, they are all norway rats also known as brown rats or common rats. They come in a wide variety of colors and coat textures, including naked and also don't have as ridged of standards to follow when breeding.
Rats should have a long racy body maintained in good weight, large bold eyes, long clean head showing breadth and length, large ears, long tapering tail, and an average body length of 8–10 inches.