Black Flies Everywhere? Moved into a new apt - its an old-fashioned building and I...

Moved into a new apt - its an old-fashioned building and I am the only part on the 2nd floor. Now that I am a week into moving I see black flies all over - Gross!!! In the window and buzzing around the apt. I will work on finding the source and have some holes I can swarm, but any other ideas save for fly tape?? They are within every room and there are so abundant of them *sigh* please help !!!
Answers:    Cotton ball with for a while dab of eucalyptus grease. Take a piece of thread and hang them surrounded by doorways, windows and the middle of the room. It repels them and they reckon the cotton ball is something that will munch through them, I guess. My mother likes to keep hold of all her doors and window open adjectives the time (she's got dogs and cats who close to to explore) and she never has any flies inside. She also hang baggies of water on her doors. Not sure what the baggies of sea do, but whatever it is works, I guess. The fly strips are gross and bizarre anyway. You can hang them outside the windowpane where you can't see it.... But flies don't resembling eucalyptus oil and ethnic group do.... so I would dribble some on the window sills.

My mom also have what I call her "tennis paddle of death." It's an electrically charged fly swatter that looks resembling a small tennis racket. You swoop it through the upper air while holding down the button and any flies that get close, capably.... zzzzt!
Close up all the doors and window and spray the room with House and Garden Raid... build sure your bedding and clothes and food are all put away.. after find out where they are coming from.. angelic luck call the tenant and let them know...