mouse(复数：mice)是指小鼠，而rat(复数：rats)是指的大鼠，是两种不同的物种。英文里区别非常清楚。
rat和mouse的区别
1、英文中mouse与rat都翻译为汉语老鼠，通常以大小来区分二者，mouse是指小鼠，rat指大鼠。
2、Mouse经常成为宠物（pet），被看做好玩（playful）、可爱（loving），而Rat被看做是邪恶的（vicious）、不洁的（unclean）。
3、mouse不含褒贬之意，rat含贬义，就像过街老鼠,肮脏,是害虫。
rat和mouse的短语
rat race 激烈的竞争；残酷、高压的生存环境
He decided to get out of the rat race, and went to work on a farm.他决定摆脱这种高压的工作状态，去一个农场工作。
smell a rat 觉得哪里不对，起疑心
He&39;s been working late with her every night this week - I smell a rat!他这周每天晚上都跟她工作到很晚，我觉得不对劲！
lab rat （实验室里的）小白鼠；长期泡在实验室的研究生；实验对象
He is in love with a lab rat and they haven&39;t seen each other for three months.他爱上了一个实验室狂魔，他们已经3个月没见面了。
mouse potato 电脑狂人（长时间使用电脑的人）
I can&39;t believe I spend 10 hours a day on the internet. I&39;m such a mouse potato!真不敢相信我一天在网上的时间有10个小时，我真是个电脑狂人！
poor as a church mouse 穷得叮当响；一贫如洗
You want to borrow money from him? He is as poor as a church mouse.你想从他那里借钱？他可是一贫如洗。
quiet as a mouse 悄无声息；沉默寡言
She was as quiet as a mouse that nobody noticed her presence.她不声不响，以至于没人意识到她也在场。
