First of all, if you want to 'translate' your dreams, you need to consider both the psychological and 'mystical' interpretations of it. Depending whether or not you are superstitious or not may impact how you interpret your dream.
Animals in dreams are often seen as a representation of people you may know; so perhaps somebody around you has acted like a 'rat'. Rats are often portrayed as filthy, dirty or diseased; sneaky, destructive or unworthy.
Symbolically they can stand for illness, distrust, disease and destruction, among others. Psychologically they can represent feelings you have such as guilt, doubt, greed, or unworthiness. Something you did in reality may make you feel like a 'rat'.
My personal opinion:
You stated that your girlfriend is afraid of rats. Maybe the rat in your dream symbolized her fears, or the fears you have concerning the safety and well being of her. Dreams are mysterious things, and there are many ways to interpret them.
From my personal experiences, since I dream quite often, my dreams can have strange bits and pieces of events or worries I have dealt with recently, or they are totally random and have nothing to do with anything that I can think of.
It means your scared that somethin bad will happen to her.
It means that your girlfriend is worried for her other friend.
The house represents a life that you could build with your girlfriend. Note that the dream does not determine or foresee any specific future, but it does express your hopes and emotions about the future.
What DOES a dream MEAN that makeS YOU scared...well its called a nightmare... an unpleasant or terrifying experience... look online to key parts of this dream to find out what it means :)
it means you do not trust your girlfriend.
If you dream about having a girlfriend, it does not necessarily mean that your man is straight; it could be due to your fears of finding out that your man is not straight.
The dream probably expresses your jealousy or feeling of being inadequate to hold the girlfriend's interest.
It more than likely doesn't mean anything; a dream is just a dream. Don't hold your girlfriend accountable for something you dreamed happened.
The dream expresses your own desires and emotions. It does not predict the future and it does not reveal your girlfriend's thoughts or feelings.
that you dont like his girlfriend
This dream illustrates your own feelings about your girlfriend rather than revealing her behavior or intensions. You might suspect that she is cheating, and the dream reveals your suspicions. That does not mean that she is cheating.
That you have not yet moved on.