I desperately want to get my fiance a pet rat for christmas.

He has wanted one for years and we have just moved in together (told him a little fib that we weren't allowed pets in our rented house so that he wouldn't buy one so I could surprise him for christmas) but would rather see here if anyone has one first before looking in the shops

He know's all about taking care of rats but I don't know the first thing so if you have any advice as well that would be appreaciated (as in the best home to buy for them, what food to get them, special things to do to keep them extra healthy and live long)

many thanks