Balsamic vinegar fruit fly trap

I always seem to have a terrible fruit fly problem at this time of the year.  One day everything is fine and the next the kitchen is crawling with the pesky little things.  I had never been able to get rid of them until halfway through this year.  Balsamic
vinegar.  Put some into a little bowl and cover it with plastic wrap.  Poke a few holes into the top of the plastic big enough so that they can get in.  Then they can't get out.  My bowl filled up the very first day and the fruit fly count is dwindling.  Very exciting.