How to Make a Fruit Fly Trap

A few years ago when I was in art school, I lived in a crappy apartment. I loved it. But it had some flaws. One of them was a neighbor who collected empty cans as a means of income. It happened outside our backdoor. One summer, flies and fruit flies began moving in...to our apartment.

Among the many things I learned in college that had nothing to do with academia, was how to smash a fruit fly in mid air. One night I sort of snapped and spent most of my evening slaughtering as many fruit flies as I could.

At the time, I went online looking for help to this problem. When the neighbor was ordered to stop stockpiling garbage, the issue was pretty much resolved. But in our apartment, the fruit flies took refuge. I found lots of ideas online for trapping fruit flies, but I'm not sure if I found exactly what I ended up doing.

Yes, of course, remove the food supply. Don't leave fruit out. They will even eat some plants. And if you have fresh cut flowers, they may nibble on those, too. I read that they will hang out in your drains. But that wasn't really our problem. Our fruit flies were surviving regardless.

So I designed a simple, earth-friendly trap that can be made with materials from around the house.

1. Take an old glass or plastic jar. You'll want something you can see through. Peel the labels off a spaghetti sauce jar or something similar.
2. Find some scrap paper and make a funnel by rolling it up and closing it with tape. Junk mail works. I like to make my funnels long and pointy so they fit in my jar with a few inches left below.
3. Remove paper funnel and put about an inch of vinegar in the jar. Fruit flies love it. They also love wine. So if you have an old bottle hanging out, that will work, too. Or maybe make a vinegar/wine cocktail for them.
4. This is the most important step. Put a drop of dish detergent in the liquid.
5. Place the funnel in your jar and leave it alone.
6. Check your jar in an hour and see how many little flies have met their doom.

Here's what will happen: The little flies will say, "Oh, yum! I gotta get a taste of this." They will go down the funnel and will either fly up to leave the jar, only to be caught at the edge of the jar, or they will try to take a little sip of the liquid, only to find that the surface tension has been destroyed by the soap! They drown. But don't feel bad. They drown doing what they love.

You'll want the jar to be see-through, because it's so satisfying to see how many flies you can catch. You might not get all of them, but it's something.