Did anyone else have rats who bit? Or was it just me?

They were petstore rats which might explain it (not my choice, I was 10, I didn't know any better then anyway!)... I remember when we went to choose our ratties they had these horrible glass doors, letting in little ventilation. When the assitant closed the door, he didn't just close it, he slammed it (idiot!) and I saw the ratties jump out of their skin. I have a really bad memory but only remember things that shocked me during my childhood, and that is one of them! I would like to have rats again in the future, fingers crossed next time they will be friendlier, and of course they will be rescues!!