3 ms·
As described in the sibling comment, a glass with a fifth of vinegar, same amount of water, and a drop of dish soap will do the trick fine. No craftsmanship nee
by johnyzee 3y ago
As described in the sibling comment, a glass with a fifth of vinegar, same amount of water, and a drop of dish soap will do the trick fine. No craftsmanship needed. The flies drop instantly when they touch the liquid.
Most people cover the glass with some cling film and punch a few holes through, but it will work fine without. The main advantage of the film is that the liquid won't evaporate away, and the trap will be good for a couple of weeks.
- xenospn 3y agoCan confirm. I have one constantly in my kitchen and it works great. Flies don’t seem to mind that I constantly dilute it by adding water to make more foam.
- Terr_ 3y ago> The flies drop instantly when they touch the liquid. To be slightly more specific, the soap changes the surface-tension of the liquid, causing it to, er, schlorp onto the insect in a way it does not expect. That reminds me of JBS Haldane's classic essay "On Being The Right Size": > An insect, therefore, is not afraid of gravity [...] But there is a force which is as formidable to an insect as gravitation to a mammal. This is surface tension. [...] > An insect going for a drink is in a great danger as man leaning out over a precipice in search of food. If it once falls into the grip of the surface tension of the water -that is to say, gets wet - it is likely to remain so until it downs. A few insects, such as water-beetles, contrive to be unwettable; the majority keep well away from their drink by means of a long proboscis.