Question: if your apt, building has mice,who's responsible for getting rid of them? 

Answer: The Landlord is responsible. If repairs are made properly,then the mice can't get in. If he refuses to do his job,or complains to you about housekeeping,or what-have-you,then file a complaint with the Board of Health. Trust me,he'll start fixing things,and be sure to tell the Board of Health to make a stipulation,that after repairs are done,your Landlord can not increase your rent.
This question from the Yahoo Q&A forum is categorized in the topic: Business & Finance