Do I have to pay rent for the time that my apt has become uninhabitable due to mice. Who pays moving expenses?

I am a lawyer in CT and practice in this area of the law.  Situations like this that are not predetermined under the lease are generally determined by what is fair and equitable.  If there is a lease that states what happens in this situation, then you and the landlord must abide by those terms.  if there is nothing in writing that speaks to this situation, then the court would seek to keep you in the same position as you were if there were no mice.  therefore, you would still have to pay rent to the landlord, however, the landlord would have to pay for your moving expenses as it is not your fault the mice are infesting the apartment.  I suggest hiring a lawyer if the landlord refuses to pay you moving expenses.  neverthless, i would compromise, if you must to split the moving expenses or receive a rent credit.  your lawyer can negotiate a resolution to take this matter to a court of law.