Yes, ferrets can get ear mites.  Just went through it myself.  The wax in
the ears builds up very fast, and is very moist.  Around here it is a very
darkish brown.
 
Don't bother with regular ear drops for mites, those are like twice a day
for a couple of weeks.  Have your vet put in a drop of ivomec in each ear.
Once is all that you need.  Treat all the animals in your house at the same
time, to make sure and get them all.  Otherwise you may have a reinfestation.
 
My vet uses a 20 guage, BLUNT tipped needle to drop the ivomec in.  Very
easy, painless and works wonders.
 
Maggie the Mad Celt,
Mistress of the Mid Missouri Mustelid Mob
 
ferret info website: http://www.missouri.edu/~c705570
personal website:    http://members.aol.com/~dragnfey
[Posted in FML issue 2148]