How to gain rid of fruit flies??? We seem to own an infestation of fruit flies. I cannot find...

We seem to own an infestation of fruit flies. I cannot find the source, as I think it may be another apartment within the building. We have NEVER have this problem before. How can I determine the source, and after get rid of the flies if the source isn't within our suite? I have pets and cannot use anything toxic.
What does this contraction have it in mind...
Answers:    Wipe everything down near beach, it works
Should I be freaked out if in that...
return with a bottle of wine and leave going on for half within it and leave the top sour .. and they will fly in in that and drown