Mine also had to be taught not to dig up the carpet. And we had to do alot of ferret proofing because Draeco loved chewing on electrical cords when he was very young. And just about the time you think you have something blocked up so they cant get into it, you find out, they actually can despite youe efforts.
SIDE NOTE: Beware they are sneaky...
A few years back, my sister got a ferret, I told her to really watch him and that he should not be out at the moment, well, he met his death inside her wall (we were putting up dry wall) and he got in there cruising the wall and decided to chew an electrical cord. Had to take the dry wall down in one place to get him out, not very pretty.