We had an outbreak of gnats and could not for quite some time figure out where they were coming from. I cleaned the drains with baking soda and vinegar as I have in the past to get rid of them and that didn't seem to work. I had resorted to leaving my vacuum cleaner sitting in the kitchen to suck them up every time we found one. It seemed like we were vacuuming all the time.
We went away for the afternoon to return home to a frenzy of them in the entrance. After vacuuming up those that didn't sneak away, my son notice the worm farm sitting in the basement; the gnats were flying out of the air holes we had made in it!
Needles to say, the worm farm is now sitting outside in the shade, which happens to be on our front porch. I'm sure we will fit in with all the other red necks in the neighborhood by having a cooler sitting on our front porch now. Just don't open it thinking there is going to be a cool beverage chilling for you. You will get a wiggly surprise. Since we moved the worms outside the gnat population has dwindled and they are no longer doing fly byes as we eat or work on the computer!