bottom teeth

Question
my girls are almost 3 months old and I wonder if the bottom teeth are normally longer than the top? (First time with rats) They have plenty of hard things to chew, although they don't seem too interested in anything but nut shells (walnut and filberts), they prefer not to chew on wood. Is that normal?
Can the top teeth become more worn down than the bottom? I don't really see how or what i could do about it if this were the case. I give them short grain brown rice (cooked) plus a tiny bit of olive oil or miso broth drizzled on rice and a variety of veggies(uncooked)twice a day. They wait for these meals... They do have daily access to their supplement food - hard pasta, cereals, oats, pumpkin and sunflower seeds,  Chinese crackers and a good dog food about every other day. Except for the dog food, oats and the 2 types of seeds they prefer to wait for their rice and veggies. Could this diet be too soft for proper teeth ware?

thanks - La

Answer
Yes, they are usually longer!

In fact, go to my website, sandyscrittercity.com and read up on rat teeth. There are alot of misconceptions you seem to be following such as the fact that they need hard food to keep the teeth filed down. This is not true.  Check out my site and the page (I want you to see the funny photos of the cutest rats SMILING for the camera) and along the way you will learn alot about their funky orange teeth!  The more orange they are, the better!!!  :)   In fact, since your a new rat owner, you may find alot of good info along the way!