A mouse is a different animal to a rat. Mice (the plural of mouse) are very small, fast running creatures. There are many different kinds of mice but I believe that there is only one species normally associated with humans. There are also many different species of rats but there are two species associated with humans - the Black Rat and the Brown Rat. Rats carry a number of diseases that can kill people. The worst being Bubonic plague, also known as the Black Death. Rats and mice both are pest animals, however unlike rats, mice are sometimes eaten by humans. They were a delicacy in Roman times and child street vendors still offer them for sale in parts of Africa

Just adding to the mouse versus rat question. There are a number of folk sayings about both animals that reflect how they act and when and where they are found. So "as quiet as a mouse" - you often never hear mice, rats on the other hand are noisy animals. 'as timid as a mouse' - mice avoid people and usually you don;t see a live one. And even a poem features a mouse. Mice are active at night. So the poem "`Twas the night before Christmas and all through the house, not a creature was stirring not even a mouse" - the word 'twas is from running together the words it + was at the start of the sentence. Rats on the other hand have a different reputation. ' dirty rat' is an insult. Rats are said to desert a sinking ship referring to their jumping into the water as a ship sinks. Rats can also attack and kill babies and sick or old people. A rat featured in the George Orwell novel 1984 for exactly this reason.

都是老鼠。

Rats are bigger than mice. That's the difference, but otherwise used in the same way.