A couple of inches of any juice in a glass works well too. Don't get any on the sides while pouring it in, this way they have to get "into it" and not off of the sides of the glass. Don't let many accumulate at a time in the glass, they will crawl on each other to get out LOL

I just did this at DB's house, a bag of potatoes was forgotten about there. I put a couple of glasses in each room and within 2 days they were all gone. :) :) :)

I've made a lot of fruit flies traps over the years for that darn fruit fly lab. The one that seemed to work the best was to put about an inch of apple cider vinegar in a mug or glass. Then, top the whole thing with a funnel (make sure there is air space between the funnel and the vinegar). This prevents the little pests from escaping the trap. Eventually, they will drown.

I use a 20 ounce pop bottle.. when u see some inside..place your hand over the top and shake them little buggers down into the cider vinegar. Flying insects can get into holes, but can not get out of holes. It is only by chance that they get out. We use this method at our apple orchard every year and we never have an issue with them.

durn gnats...
 

I put a little sweet wine in a drinking glass...covered it with saran wrap... put a rubberband to hold it in place...punched small holes in the saran wrap. I placed the glasses in infested places.....within a week I had them gone. Dampness as well as fruit seems to attract them.