Do you have a cat, or know anything about them
Yes i do, i love cats so much! The domestic cat (Felis Silvestris Catus) or (Felis Catus) is a small, furry, carnivorous mammal
Are they known for being friendly
Well good question, they are often valued by humans for companionship and for their ability to hunt vermin, so i would say yes they are friendly but you do get some that are not so much. 
What kind of vermin do they normally hunt
I'm not exactly sure, although i know they definitely hunt rats!  Do you own a cat? 
I do own a cat, he just stays inside though.
Thats cute! there's more than 70 cat breeds in the world!