Young Ferrets and litter training

Question
Is there anything else I need to know really about it? From what I can see they are very well mannered for being so young. I assume the cewing on toys is just them being them. As for foods and so forth is there anything that is better then the rest. Its been a few years since I have had my last ones

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-----Question-----
My wife and I just got 2 baby ferrets 9 week old female and 11 week old male as in the cold Michigan weather we need something fun around the house as I work.
I have had ferrets before and I guess I was lucky enough that they took to the litter training like a cat.
For example:
Place litter box in cage and it was the holy shrine of pooh.

This time around the 9 week old girl is catching on she has been batting 100% the past 2 days the boy however has not.
I have been using the training method of when they wake up keep a close eye on them if they try to "back up" to do the dirty work to put them in the litter box and make sure they go in there.
Is this the way I should be going about this or has my research done me wrong?
I have taken the liberty of putting food dishes, water dishes a bedding house type thing in his usually places to prevent him from doing so.
Any feed back would be great.
-----Answer-----
Congratulations - you are doing everything right!  More often that not, ferrets are not 100% about using a litter box.  I have 7 and I would say 1 is 100%, 4 are 75% and 2 are like - whats that - a fun place to dig?

Patience and vigilance may help or he may just be a ferret that doesn't completely get it.
Sorry I couldn't give you the secret tip!
Ailigh

Answer
Some chewing can be a problem - if they are chewing on blankets etc then it can wear their teeth down.  The only way to stop this is to remove the blanket.  The rest is probably young ferret chewing - make sure they have ferret safe toys to play with.  Baby toys and hard rubber dog toys work really well.

We feed Natural Gold ferret food.  It is made by Pretty Pets and is a high protein/lo carb food.  High carb food has been linked to Insulinoma in ferrets.  They need a high protein and high fat food in general.  They are obligate carnivores so no veggies or fruit.  Natural Gold is also more brittle than normal kibble so it is better for their teeth.  I also feed raw chicken- good for teeth and overall health.  We chop the chicken into small pieces if they aren't used to real meat!  We use a variety of other ferret food (usually free samples) as treats.  Totally Ferret Baby food is another good food.

Make sure you have a ferret knowledgable vet - keep an eye out for Adrenal and Insulinoma.  Make sure they are vaccinated for Rabies and Canine Distemper.  Also - ferrets are naturally burrowing animals so providing dark areas is great - a rubbermaid rub with a lid and a hole cut out makes a nice nest box for them.  Over exposure to light is thought to lead to Adrenal as well as early spay and neuter (which we can do nothing about).

A really good resource is Ferrets for Dummies.  Goes over basic stuff but also much more detail too.  We have a routine of trimming nails, cleaning ears, brushing teeth and weighing all of ours this helps them but it also helps us keep track of any problems early.  They don't need a bath very often (we go like once a year or so) but they do need out of cage safe play time.  

Hope this helps
Ailigh