Tail spots??

Question
I bought my first baby girl rat from Petsmart about 2 months ago and she's growing beautifully.  But recently, I've noticed that she has a few small red spots on her tail, not scabs or cuts, just spots.  She doesn't react if I touch them, and I've been careful about giving her only things that can't hurt her (most of her toys are light weight cardboard or small wooden pieces).  She doesn't come out of her cage much, and when she does I mostly keep her in a ball so she can run around the house without the threat of our cat.  Do you have any suggestions about what these spots are, and if they need to be treated in any way?
Thank you.

Answer
 If they are at the base of her tail and they are small raised lumps they are probably bites from mites.  I would recommend treating her for parasites just in case; the treatment is safe even if she doesn't have them and at least you can rule that out.  Apply one drop of Advantage or Revolution (flea killer solutions for dogs and cats) to the skin at the back of her neck and another in two weeks.  In the meantime clean her cage really well, and to prevent future infestations freeze all bedding to be used for 24-72 hours before use.  If that doesn't get rid of the spots and they aren't bothering her (they aren't itchy, getting larger, or changing in color) they may just be normal or just a small irritation that isn't bothering her.  Also, if they are more of a brownish red it could be urine; rats sometimes don't groom their tails very well and they can get some blotchy spots of a reddish orangish color from dragging them in urine.  Caging with plastic shelving that is solid is especially bad for this.  If you notice them getting bigger, changing in color, or bothering her in any way I would recommend you take her to the vet for an exam.  I hope that answers your question, good luck with your rat!