A cat come into our house if ever any downstairs window is left open, even those little ones that are above big windows (you know what i mean). One time I tried to chuck it out because I wanted to go to bed and it didn't appreciate it. It attacked me and almost took my eye out. Really, I was so lucky. As it is I was left with prominent scars above my right eye and on my left arm. I remember putting my hand up to my face for a few seconds, taking it away and not being able to see any skin through the blood that covered my hands. I spent ages looking for that cat afterwards, the little bugger.
My cat used to go into my next door neighbours house via their cat flap and steal things: Food of different kinds, toys for their baby and their cats* and, at one point, a very large feather duster. I was quite impressed that he'd managed to get a feather duster through 2 cat flaps. He also stole the dads birthday cake. Unfortunately they have a dog now so we have to stop training him to steal wallets
*He used to steal their cats toys. He didn't used to steal their cats.