I've never been bitten 'for real' by a rat. I can imagine though.
My boys (2 pet rats) are sooo sweet, they'd never bite. On the other hand, my breeder rats are awful.
Just shows you the difference between rats handled when they are young.. and not. I got my boys from a breeder. Great pets.
I don't even want to know what a bite from a rabbit would be like. Killer teeth!