I need some food changing tips. I know that you can sprinkle the new food on the top, but is that all?
Also are these foods okay:Amazon.com : Wysong Uretic Feline Dry Diet, 5-Pound : Dry Pet Food : Pet Supplies,
and Amazon.com : Wysong Vitality Feline Dry Diet, 5-Pound : Dry Pet Food : Pet Supplies?
They are eating Marshalls right know and i just want them on something better. Thanks, Ian

If you're going to go with Wysong, I'd choose this (http://www.amazon.com/Wysong-Epigen-Digestive-Support-3-Pound/dp/B00M42P6SS/ref=sr_1_sc_1?ie=UTF8&qid=1412796258&sr=8-1-spell&keywords=wysong+diigestive+supprot) over those other two. 
Too high in fiber, and some less than ideal ingredients (peas, rice)

Nature's Variety Instinct Duck, Wellness Core, and Orijen are also very good. 

It's best to do a mix of foods, that way if one food is ever unavailable, you have another food your ferret is used to.
 I personally prefer to have at least 1 food you can get locally (NV and Wellness can both be found at Petco and Petsmart), so if your online shipment is late, you have a food you can get easily

Ferrets: Wesley, Percy, Owen    -rip Bandit-
Bettas- Kitty, Pip, and Logan
Sun Conure- Kita
Gerbils- Piper and Tailer