Mouse vs. Rat

A rat (noun) is a large-sized rodent that will often scavenge for food. They are often found in subways and sewers or even in or around people's homes. They are considered a pest.

A mouse (noun) is a small-sized rodent that also will scavenge for food. A mouse is capable of infesting a home, building, or other enclosure if there is an available food source. They are considered house pests.

*Hint/Tip: The main difference between a mouse and a rat is size. A mouse would fit in your hand, and a rat may be mistaken for a small cat.