Rats have thicker tails, larger heads and smaller ears than mice. Mice tend to weigh roughly 3.5 ounces, while rats weigh, on average, at least a pound. Rats also live roughly half a year longer than mice and have larger feces. The feces of a mouse are about the size of a rice grain. Rat droppings are the size of a raisin.
Rats tend to be larger than mice in general, but different species of mice and rats may have different characteristics. For example, house mice have a naked tail free of fur, while mice that live in less urban areas often have a furrier tail. Rats generally have a long, naked tail. Mice have narrow, sharp muzzles. The rat muzzle tends to be more rounded off and blunt, with a wider shape than that of a mouse. Mice do not tend to dig very deep burrows, while rats love to dig burrows deeper underground and make extensive horizontal tunnels. The head of a mouse has a triangular shape and is small in relation to the size of its body. A rat has a proportionally larger, broad head. Rats are also more intelligent than mice and can be taught tricks.