An average adult house mouse weighs between 17 and 25 grams, or .03 to .05 pounds. They are about 169 millimeters or a little over 6.5 inches in length.
Mice have short hair and large, hairless ears that are generally brown. Mice usually have a yellow colored flank, black or grey under fur, and may be speckled. They have long tails with a brown-black tip, and the tail is paler on the underside. The tips of their toes are generally white.
While mice can be found throughout the United States, they are not native. They likely came over on boats and settled in seaports with early immigrants.