Yeah! The tip never touches the vinegar, and you can move it around a bunch because the sloshing vinegar never touches the cone tip. The flies can’t get back out from the cone tip, they don’t understand how it works. I used to have a dirty roommate and have used this trap tons of times when he’d leave empty beer bottles and stuff around.

I’ve also heard of soap! I’ve never tried it though, because this fruit fuck paradise trap works amazingly and is fascinating.

There’s an example here, but i have perfected it by using slightly thicker paper, trimming the cone 2cm above the jar’s lid for aesthetics, putting fruit slices in there, and making the cone’s tip much smaller (maybe 5mm to 1cm wide at the tip.)

It never fails. It’s amazing. And once they’re in full fuckfest mode and larvae start to spawn, it’s fascinating.

Edit: you absolutely want apple cider vinegar. Red wine vinegar or actual wine might also work, but apple cider is what I have had AMAZING success with.