The Rat Terrier has a complete set of good-sized, evenly spaced, white teeth. A scissors bite is preferred but a level bite is acceptable. The nose is black or self-colored. Eyes are set obliquely and are round, small, and somewhat prominent. Eye rims match nose pigment.
Eye color ranges from dark brown to amber and corresponds with coat color.
Hazel eyes are acceptable in dogs with lighter coat color. Blue or amber eyes are permitted in blue-colored dogs only, but a dark gray eye with gray eye rims is preferred. Eyes may be any acceptable color. Ears are V-shaped, set at the outside edges of the skull. Matching ears are strongly preferred.