<human>:  I'm wondering what's the difference between a rat and a mouse?
<bot>: The main difference between a rat and a mouse is in size. Rats are generally larger in size, around 20-25 cm in length, whereas mice can be as small as 3-12 cm in length. Rats tend to have thicker fur and proportionally larger tails while mice are covered in finer fur and have smaller tails. Additionally, rats are social animals and often form small groups while mice are more independent and tend to live alone.