Litter Training
Litter Box
A ferret litter tray or box should have one lowered side so that the ferret can easily walk in and out. The other sides of the tray should be fairly high, as ferrets like to back themselves into a cornet to do their business. A good tip is to leave some feces in the litter tray all the time so the ferret does not try to play inside the litter tray. Note that you can use normal cat litter as ferret litter.
A sleeping area dedicated for sleeping and resting is needed for your ferret that contains all the appropriate bedding. If you have a wire cage you should place a box inside with bedding inside, they will not be happy with sleeping in the open cage as you can easily see through the wires. You should fix the box to the side of the cage so your ferret does not drag it all about the cage, they could easily drag it into the litter side of the cage and it end up soiled and need cleaning.
Litter Training
Litter training is possible, although ferrets do not naturally take to it as well as cats. Providing a stable litter pan that can be firmly attached to the cage is the first step. Start off keeping your ferret and its litter pan in a small area i.e. by confining the ferret in the cage and even blocking off part of the cage if necessary so there is limited space for the ferret to do it's business. Part of the pan must have a low edge to allow the ferret easy access, although part of it can be high walled since ferrets like to back into a corner and may overshoot the edge of a low pan. Do not keep it meticulously clean - placing or leaving a small amount of urine or feces will reinforce that this is a bathroom area (the key being a small amount - the ferret may not use it if it is too dirty). Keep the rest of the cage a sleeping (lots of cuddly bedding) or feeding area. Place the ferret in the litter box before taking it out to play, and return it to the box frequently during play or any time the ferret looks as if it may be getting ready to urinate or defecate. If you manage to catch your ferret using the litter box, be sure to reward him or her with a treat! If you catch your ferret having an accident, place him or her in the litter box - although this has to be done immediately after having the accident to have any effect at all. Never hit or yell at your ferret, just place him or her in the liter box. Once the ferret catches on you can place litter pans in the room(s) in which the ferret plays. You will want to have a few litter pans placed strategically as the ferret is not likely to wander far in search of a bathroom. If you notice a corner or area where the ferret likes to go, that would be a good place for a litter pan. If your ferret picks a place that is not good for you, try placing some food there so that the ferret will think it is an eating area and therefore not a bathroom. It is a gradual process and since ferrets are not as fastidious as cats, expect some accidents. The key is to reward successes, and never, ever, punish for accidents. Patience and consistency will definitely be necessary.