Occasionally during the summer when I have a lot of fresh ripe fruit on hand I have a slight problem with fruit flies but, I usually get them under control with in a day or two.
This past month we having been battling fruit flies beyond what I had ever experienced before. No amount of making sure there was never any food left anywhere and keeping things sparkling seemed to help. And the place where they seemed to like living the best was in the bathroom. Which was very disturbing to me.
After googling for a solution the most common answer that popped up was that they were living in the drain and that boiling water should resolve the problem. I immediately got a big pot of water boiling and poured it down the drain. I could tell that it helped some but in a few days it was a bad as ever.
After more investigation I started blaming it on the bottle of hand soap we were using. Inspector Hector Dirt Detector was a new thing we had picked up over a month earlier. The children thought it was fun to use since it had these funny little particles in the soap that were supposed to change color once their hands were clean. To test my theory a little more I put a few drops on the side of the sink and it wasn't long before fruit flies were swarming all over it.
I put a new bottle of soap out and our fruit fly problem has vanished. Inspector Hector will not be welcome back into our house again!