Put vinegar in pop bottle , cover with cerand wrap, poke holes in top. Let it set,bugs ( nats) will be drawn to it.
Marie has a good idea, but take it a wee bit further and make that Apple Cider vinegar instead of plain vinegar. I have never used Saran wrap, the Gnats just seemed to commit suicide and stayed in the bottle without it. You need to find the source of the gnats, such as house plants, sink drains, fruit out on a cabinet, or anything similar and remove the problem. Good luck. 🌹💖😘
Hi Vicki: Here's a site that tells you all about this:
I have even put the apple cider vinegar, squirt of dish detergent, and water in a small open bowl and it worked great.