I've wanted a ferret for years.
But my mother thinks they're rodents (they're not!) and is afraid of them, my dog would want to play with it and it'd probably bite him, and I'm afraid of them to a certain degree.
When I go to a petstore, and I'm looking at the ferrets, I usually stand at a good distance because the cage does say they bite.
And I've seen one freak out before.