Put a drop of soap in the vinegar

Two things, the accounts say, and neither is the trap. First, the bait: one correction and two accounts in one objection say red-wine vinegar does not draw them and cider vinegar does; single accounts swear by malt vinegar, balsamic, a layer of red wine on top of the vinegar to hide the soap smell, beer, sugar water, or a piece of over-ripe banana, and one exchange, one account each way, argues malt against cider and another argues balsamic against cider, which is to say the flies have preferences and the accounts do not agree what they are. Six separate conversations say the principle under all of them is that the flies come to anything sweet and fermenting, and three conversations say an open bottle of cheap sweet fortified wine cleared a whole flat overnight — with the objection, from two accounts, that the flat in question had not been cleaned, and one account’s note that other wines may not do the same. Second, the door: one account says the soap is what stops a fly standing on the surface of the vinegar and walking off; one caution says the film has to be sealed to the rim or they will not go in; one account uses a paper cone in a jar instead of film and found it caught far more than an open cup; one account baits a zip-seal bag with fruit scraps, leaves a small hole, and once the flies are in seals it and throws the whole bag away. One caution says a trap is also an advertisement — it can draw flies in from elsewhere in the house — which is why it goes where the flies already are. How long a trap keeps working and how to empty one are asked in these conversations and not answered.

From inside the house, three separate conversations say, not from the window: a fruit fly lays eggs on the fruit or in the rot, and the cloud that appeared overnight hatched, one account says, rather than arrived. Three conversations say removing the breeding place comes first — the ripe bananas, the bin, the drain, the waste disposal, the dishes — and one account puts it as source first, trap second; one caution with two accounts says traps kill the adults and do nothing for the eggs, and another with two says traps alone do not solve it while breeding grounds remain, so a clean kitchen with a trap in it is the only version that ends. One account says new eggs arrive on the produce itself, bananas especially, and one exchange, two accounts to one across two conversations, argues whether washing fruit when you bring it home stops them — the two say it removes the eggs, the one says the life cycle would show larvae in the fruit if that were where they bred, and this page does not settle it. Two conversations say the drain: pour boiling water down it and clean it out, and one account pours bleach, which this page carries as one account’s. Then the correction that changes the diagnosis: one correction says flies living in the sink drain are drain flies — hairy, and they scuttle rather than fly well — not fruit flies, and they want a cleaned drain, not a vinegar cup; one account says flies rising from the soil of a houseplant are fungus gnats, which want the soil drenched with soapy water or oil and are not caught by the trap, and one correction says the yellow sticky cards sold for them count the population and do little to lower it. If the trap catches nothing after a night, one caution says look again at what the insect is. One account in a shared flat says nothing works unless the whole household is doing the same thing, and one objection says an infestation with a hidden nest cannot be ended until the nest is found.

All in these conversations, with their counts, and none of them the page’s counsel. Three separate conversations vacuum the flies off the walls and out of the air — they are weak fliers, those conversations say, and the hose catches them — with one exchange, one account each way, unsure whether the flies die inside the machine, and one account’s caution that eggs can hatch in the bag if it is not emptied; one exchange of three accounts to two prefers a flame for speed, and the two say the vacuum is easier and less unpleasant. Several single accounts turn every light off but one, wait for the flies to gather on it, and take them with a lighter or a candle, and four accounts in one objection say the candle version is simpler; these conversations’ own list of gaps includes what to do about curtains near a flame, and this page adds nothing to that except the obvious. Two single exchanges, two accounts to two each time, argue whether a pan of simmering vinegar kills them: two accounts say the fumes drop them in minutes, two say it did nothing but burn their own eyes and made the flies livelier, five single cautions say the house smells of vinegar for hours and the fumes sting the eyes, and three contraindications in these conversations say the same thing three times — do not do this in a home with a bird or a small mammal, because the fumes can harm them. One account sprays the flies out of the air with rubbing alcohol; one swats them with a racket; one says window screens keep the next generation out, and one caution says a trap does nothing about flies coming in from outside. If the flies are the big slow kind that ignore the vinegar, one caution says those are house flies and want a different page; the linked one is theirs.