Here are a few resources you can use to prove they are not rodents.  (I
think it's stupid you can't have rodents as pets, anyway.)
 
Also, try the National Geographic's North American animals book.
 
http://www.geobop.com/Mammals/Carnivora/Mustelidae/
 
http://www.ferretcentral.org/faq/part1.html#what_are
 
http://members.tripod.com/ffgmweb/what_is_a_ferret.htm
 
http://home.worldonline.nl/~wfu/ferret.html
 
http://www.ferretguardian.org/f_facts/whatis/whatis.html
 
http://hometown.aol.com/fscottg/index.html
 
You can find great scientific resources even at your public library for
this purpose, too.
 
Domestic ferret: Mustela putorius fero
Classification:  Phylum-Chordata; Class-Mammalia; Order-Carnivora (NOT
RODENTIA!); Family: Mustelidae
 
Good luck!
 
 
Another tidbit that may help Anonymous re: ferret bite (from
http://www.ferret.org/read/vaccinations.htm )
 
Rabies Fact
 
Although there have been fewer than 20 ferrets ever reported rabid in
the U.S., the vaccine is safe and efficacious in preventing rabies in
ferrets.  All ferrets should be vaccinated against rabies.
 
-April AC
[Posted in FML issue 3961]