Until last year. Last year I found a natural, safe solution. This is a trap anyone can make with normal things found around the house.
I fill a short juice glass with apple cider vinegar (I don't use raw for these purposes--too expensive, I just use the generic store brand). Then I just drop a drop of dish liquid onto the surface to break the surface tension. The vinegar attracts the gnats and since the surface tension is broken, they drown.
I keep this glass in my kitchen and refresh it with water as needed or just throw it out and make a new one.
I have tried a small ramekin (6oz.), but it didn't seem to work. I don't know if the edge makes a difference, perhaps the gnats had too much area to climb out with. I don't know. But the juice glass works wonders.
[caption id="attachment_410" align="aligncenter" width="180" caption="6 oz. Ramekin"][/caption]
Now we no longer have to suffer every summer with annoying gnats!
Tip: It seems to take a couple days to work, so give it time. But after that, you should be gnat-free.
Hope this is helpful. If you have a natural bug repellant tip, please share!