Ok, so lately we have had a fruit fly infestation in my kitchen due to an old tomato. A TOMATO! I knew I hated that fruit/vegetable for a reason. I had tried everything to get rid of these pesky little buggers, but no such luck. I tried bleach, old fruit in a bag, nada. On my last and final attempt before I went officially nuts, I resorted to Apple Cider Vinegar. Hello old friend, I knew that you were good for more than bbq marinade!
All I had to do was take a plastic container (old tupperware perhaps), and fill up with 2-3 tablespoons of water, 1 tablespoon of dish soap (or a hearty squeeze), create suds and then pour in about a teaspoon of Apple Cider Vinegar. Within minutes, you will see the flies attracted to the sweet smell of the vinegar and start dying in the syrupy liquid.
After 30 minutes, I went to check on my little science experiment, and I am happy to report that we are now fruit fly free!
For other effective methods, check out THIS website.