Why are my rats itchy?

Question
QUESTION: I recently got two young female rats from a breeder. They have been very healthy and active. But they often stop whatever they are doing to scratch themselves. Sometimes they scratch with their back foot, and sometimes they nibble at themselves quickly and then stop. I once had a vet inject my past itchy rats with a med to kill mites...I don't remember if it worked, I just remember that he did a skin scraping to see very small mites. I don't have $ for a $150 vet appointment, so I'm hoping there are some safe home remedies I can try. I have asked so many people about this, and they say that mites would be visible crawling around on the skin or bedding. Is this true that I could see them for sure? The ratties have a healthy diet and lots of fresh veggies. I use Carefresh and clean their cage very often. I do not really notice much skin irritation or scabbing, but I keep their nails cut short.The way they act, it just seems like they have something biting them constantly. But people have told me it might be food allergies etc! Please, I would really love any info you can give me. My basic questions are: does it mean it's not mites just because I can't see them? And what can I try that won't endanger my ratties health. Thank you so much.

ANSWER: What is their diet?  It may be healthy to you but what is the protein levels?

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QUESTION: I buy their diet from a small local pet store. It is a mix of pellets, what looks like dog chow, grains, seeds (I see sunflower and some peanuts out of shell) and corn crushed. I've read so much confusing diet info for rats online, I just kind of gave up on finding one I feel confident about feeding...the pet store owner sells her mix with much confidence, so I buy it. I've read about no corn...no peanuts...etc, but that kind of a mix is just not available in stores. The lady I buy from uses bagged bulk food with no preservatives and is very proud of this...I do question whether or not she really knows how to feed rats. I cannot tell you how much protein is in the food, because I buy it from a bulk bin that gives no nutritional info. My concern with mixing my own food is that some nutrient will be left out if I get my recipe from a bad source. Can you tell me how to mix (I don't have much money) or recommend a brand and site to buy it. Thanks for your time :)

Answer
I can understand how easy it is to get confused on the net with all these different variations of rat diets.  Check out my website and my page on proper nutrition and this way you know your heading in the right direction!

http://www.freewebs.com/crittercity/ratsandahealthydiet.htm