How to Get Rid of Fruit Flies in Your Ontario Kitchen (and How to Tell Them From Drain Flies)

Quick answer: Most late-summer “fruit fly” problems in Ontario kitchens are one of three species with three different sources. True fruit flies breed in ripe produce and spills — remove the source and they are gone in about a week. Drain flies breed in the biofilm inside a drain and will ignore every vinegar trap you set. Phorid flies mean something is decomposing where it should not be, sometimes a broken drain line under the slab. Identify first, then treat the source. If flies persist more than two weeks after a proper clean-out, it is a structural problem, and general insect treatment is $475. Call (705) 302-1887.

Every year around the second week of August, kitchens across the GTA fill up with small flying insects that were not there in July. Ontario produce hits the shelves, green bins get heavy, cottage coolers come home half-emptied, and suddenly there is a cloud over the fruit bowl.

Then people do the same thing: they search “how to get rid of fruit flies,” find an American article about apple cider vinegar traps, set out a bowl, and get nowhere. Not because the trap is bad — it is fine, for actual fruit flies — but because roughly half the time, what is in the kitchen is not a fruit fly at all. This guide is about telling them apart first, because the fix is entirely determined by which one you have.

The three small flies in an Ontario kitchen in August

Fruit flies (Drosophila)

What they look like: About 3 mm, tan to brownish body, and the giveaway — bright red eyes. They hover in a loose cloud and land on fruit, spilled juice, and the rim of the recycling bin.

Where they are actually breeding: Fermenting sugars — overripe bananas and tomatoes, a splash of wine behind the bin, an unrinsed beer can in the recycling, residue in the bottom of a green bin, the sticky spot under the toe kick where something spilled six weeks ago.

The important number: a fruit fly goes from egg to adult in about 8 to 10 days at Ontario summer room temperature, and a female lays several hundred eggs. That is why “there were three yesterday and forty today” — and also why the problem ends fast once the breeding site is gone.

Drain flies (also called moth flies)

What they look like: Smaller and darker, distinctly fuzzy, with rounded wings held roof-like over the body — they look like tiny moths, not tiny flies. They do not hover. They sit on walls near a sink or shower and make short, fluttery hops when disturbed.

Where they are actually breeding: The gelatinous biofilm coating the inside of a drain pipe, a floor drain, an overflow hole, or a rarely used basement or ensuite drain. This is why the vinegar trap fails — they were never looking for fruit. The tell: they appear near one specific fixture and are most numerous first thing in the morning. A basement floor drain, laundry tub, or spare bathroom nobody uses is almost always the room.

Phorid flies (humpbacked flies)

What they look like: Similar size to a fruit fly, but dark, with a visibly humped back, and a distinctive habit — instead of flying away when disturbed, they scurry rapidly across a surface in short bursts.

Where they are actually breeding: Decomposing organic matter, often somewhere you cannot see — a cracked drain line under a basement slab, sewage-contaminated soil, a dead mouse in a wall void, sludge under a dishwasher or a fridge with a leaking defrost pan. Phorid flies are the only one of the three that is regularly a symptom of a building problem rather than a housekeeping problem, and persistent ones in a basement deserve real investigation.

Full identification detail on all of these — plus the house flies, cluster flies and blow flies you will meet later in the season — is in our common flies library page.

What actually works, in order

Step one: find the source, do not chase the adults

Every fly you swat is replaceable within a week. The breeding site is the only thing that matters, so spend twenty minutes finding it before you spend a dollar on anything.

The practical method: put a strip of clear tape sticky-side-down over each drain in the house overnight — kitchen, bathrooms, laundry tub, basement floor drain — and check it in the morning. Flies stuck to the underside mean that drain is the nursery. Nothing on any tape means the problem is above the drains: fruit, bins, or a spill.

Step two: if it is fruit flies

Refrigerate or remove all ripe produce for a week. Not “put it in a bowl on the counter” — out of the room.
Rinse every container going into recycling. The residue in one juice bottle is enough.
Empty and wash the green bin and its lid, including the rim where the lid seals. This is the number one missed source in Ontario homes, because the green bin program means fermenting organics live in the kitchen all summer.
Check under and behind the fridge and dishwasher, and under the sink toe kick, for old spills.
Then set vinegar traps: apple cider vinegar with a drop of dish soap to break the surface tension. The trap mops up survivors; it does not solve the problem.

Done properly, a true fruit fly problem is over in seven to ten days — one generation.

Step three: if it is drain flies

Vinegar traps and sprays do nothing here. You need to remove the biofilm.

Do not just pour boiling water down. It cools too fast and misses the pipe walls above the water line, where the film actually is. Bleach does not work either — it runs straight through without digesting organic film.
Use a stiff drain brush on the pipe walls as far as you can reach, then follow with a bacterial or enzyme drain cleaner — the kind sold for grease, not for clogs — and leave it overnight without running water. Repeat after a week; biofilm regrows.
For a rarely used basement floor drain, the trap may also have dried out. Pour a litre of water in monthly to keep the seal, which also stops sewer odour.

Step four: if it is phorid flies, or if nothing works

If you have run a proper source clean-out and still have flies two weeks later, stop buying products. The source is somewhere a homeowner cannot reach — inside a wall, under a slab, behind an appliance, or in a drain line that has failed. That is when this becomes a pest control call rather than a cleaning task, and it is worth doing before it becomes a plumbing bill.

When is this actually worth paying for?

Usually it is not, and we would rather tell you that. The large majority of August fruit fly calls we take in Mississauga, Etobicoke and across the west GTA are solved by the green bin, the fruit bowl and the recycling — no treatment needed. A company that books a $475 job for a bowl of overripe peaches is selling you something you did not need.

It is worth a professional visit when:

Flies persist past two weeks of genuine source removal. Something structural is feeding them.
You have identified phorid flies — especially in a basement, near a floor drain, or with any smell.
It is a commercial kitchen or a rental you manage. The health-inspection stakes and the number of possible sources make guessing expensive.
Flies come with a smell and activity in a wall. That usually means a dead rodent, which is a different job entirely.
Multiple units are involved. In a Burlington or Mississauga condo or multiplex, a drain-line issue in one unit routinely presents as a fly problem in three.

When it is a treatable insect problem, general insect treatment is $475, and it covers crawling insects around the structure as well. If it turns out to be a recurring seasonal pattern rather than a one-off, an annual plan is usually the better arithmetic — you can see what full coverage includes on our residential pest control page, or run the free quote quiz for a two-minute recommendation with no phone call.

The late-summer sequence to expect in Ontario

Fruit flies in August are the opening act. The order is fairly reliable across southern Ontario:

Mid-August to early September: fruit flies peak, driven by harvest produce and full green bins. Drain fly complaints rise at the same time because summer water use has fed the biofilm.

Mid-September to October: cluster flies — the big, slow ones that gather on sun-facing walls on warm autumn afternoons and then turn up at south-facing windows all winter. They are not a hygiene problem at all; they overwinter in wall voids and attics and have nothing to do with your kitchen. They are also the one fly where prevention has to happen before they move in.

Winter: whatever went into the walls in October comes out at the windows on the first warm day in February.

If you get fruit flies sorted this month and seal up before the cluster flies stage in September, you skip the whole chain. To confirm which fly you are looking at, the common flies identification page is the place to start.

Questions about something you are seeing right now? Call (705) 302-1887. Quotes are free, and if the answer is “wash your green bin,” we will say so.

Frequently asked questions

Why do I suddenly have so many fruit flies when there is no fruit out? Because fruit is not the only fermenting sugar in a kitchen. The common hidden sources are the green bin and its lid seal, unrinsed recycling, a spill under the toe kick or behind the fridge, a mop bucket or sponge, and the drip tray under the fridge. If tape over the drains catches flies overnight, you have drain flies rather than fruit flies, and the fruit was never the issue.

How long does it take to get rid of fruit flies? About seven to ten days once the breeding source is genuinely gone — one generation. If you are still seeing them after two weeks, you have not found the source, or you have a different species.

Do apple cider vinegar traps actually work? For true fruit flies, yes, as cleanup. They catch adults, which is the least important part of the problem. They do essentially nothing for drain flies or phorid flies, which is why so many people conclude traps do not work.

How do I tell fruit flies from drain flies? Fruit flies hover around food and have red eyes. Drain flies are fuzzy, moth-shaped, sit still on walls near a sink or shower, and hop rather than hover. The overnight tape-over-the-drain test settles it.

Will pest control get rid of fruit flies? Treatment kills adults, but if the breeding source is still there the flies return within the week. Any honest company finds and addresses the source first. If the source is unreachable — inside a wall, under a slab, behind an appliance — that is exactly when professional work is worth the money.

Do you service the GTA for fly problems? Yes, across Mississauga, Etobicoke, Burlington and the wider GTA, Halton, York, Durham, Simcoe County and Muskoka. Call (705) 302-1887.