How do I get rid of fruit flies with vinegar and dish soap?
Fill a short glass with an inch of cider vinegar, add one drop of dish soap, and leave it uncovered overnight. The vinegar smell draws the fruit flies in, while the soap breaks the liquid's surface tension so they sink instead of resting on top. Set it at night and check it the next morning.
How to do it
- Fill a short glass with cider vinegarPour about an inch of cider vinegar into a short glass. The smell is what draws the fruit flies in.
- Add one drop of dish soapA single drop breaks the vinegar's surface tension. Without it, the surface holds the flies up instead of letting them sink.
- Leave it uncovered overnightSet the glass out at night and leave it open. The flies are drawn in by the smell and sink into the liquid.
- Check it the next morningLook at the glass with your morning coffee to see the trapped flies.
Questions that come up
Why does it have to be uncovered instead of covered with plastic wrap?
In this method the glass stays open overnight so the vinegar smell can draw the flies straight in. The dish soap is what traps them: it breaks the surface tension so they sink rather than landing and flying off. No cover or poked holes are needed here.
What if I don't have cider vinegar on hand?
The script specifically uses cider vinegar because its smell attracts fruit flies. Other fermented or fruity-smelling liquids can work on the same principle, but cider vinegar is the one described here, so that's what's guaranteed to draw them in with a drop of soap.
Do I need to replace it every night?
The script covers a single overnight setup checked the next morning. If flies remain, setting a fresh glass again is reasonable, but that goes beyond what's described. One drop of soap in an inch of vinegar is the whole method as given.
Full transcript
Fruit flies? A drop of dish soap in cider vinegar sinks them. Fill a short glass with an inch of vinegar, and leave it uncovered overnight. The smell draws them in, but the surface holds them up. One drop breaks that surface tension, so the liquid gives and they sink. Set one tonight, check it with your coffee.