Is a mouse a rat?

A mouse is not a rat, although both are rodents in the family Muridae and share many similarities, they are different species with distinct physical characteristics, behaviors, and sizes. House mice are species Mus musculus, while common pest rats are Norway rats Rattus norvegicus and roof rats Rattus rattus. Mice are much smaller, typically two to four inches long excluding the tail, weighing half an ounce to one ounce, with relatively large ears and eyes compared to head size, pointed noses, and thin tails with fine hair. Rats are larger, seven to nine inches long excluding tail, weighing five to eighteen ounces, with thicker bodies, smaller ears relative to head, and thicker tails. Behaviorally, mice are more curious and more likely to explore new objects quickly, while rats are more neophobic and cautious. Both breed rapidly but rats have larger litters. Mice leave smaller droppings about the size of rice grains, rats leave larger pellet droppings. In terms of pest control, methods overlap but trap sizes differ. So while a mouse and a rat are related and both are called rodents, a mouse is a distinct animal and not a young or small rat, and they do not interbreed.