Why are there suddenly so many flies in my apartment?

Something is breeding nearby. Fruit flies can complete a life cycle in about ten days in warm conditions and a single female can lay hundreds of eggs, so one forgotten piece of produce or an unrinsed recycling bin can become a swarm within two weeks. Find and remove the breeding material and the population collapses.

How do I get rid of drain flies permanently?

Physically clean the drain. Drain fly larvae live in the gelatinous organic film coating the inside of drains and overflow pipes, so lasting control means removing that film with a stiff brush and hot water — not just pouring bleach, which runs past the film without stripping it.

Do fruit flies just go away on their own?

Not while food is available. With a roughly ten-day life cycle in warm apartments and hundreds of eggs per female, fruit flies persist as long as fermenting material — produce, juice residue, a wet mop, a slow drain — is available. Remove it and adults die off within days.

Why does my building's trash room have so many flies?

Garbage and organics are exactly what house flies and fruit flies breed in. Compactor rooms, chute bottoms and shared compost bins that aren't emptied and cleaned on schedule become building-scale breeding sites. Report it to management — in-unit cleaning can't fix a trash-room source.

When should I call an exterminator for flies?

When flies persist after you've removed every breeding source you can find, when the source is in shared building areas you can't access, or when large numbers of house flies suggest a dead animal or sewage issue in a wall or void. Professionals find hidden breeding sites and treat areas residents can't.

How to Get Rid of Flies in a NYC Apartment (Fruit, Drain & House Flies)

Which fly is in your apartment?

Identify before you clean, because each fly breeds somewhere different. Killing adults is temporary; finding the breeding site is the cure. The three flies NYC apartments actually get:

Fly	Looks like	Where it breeds
Fruit fly	Tiny, tan, red or dark eyes; hovers near fruit and bins	Fermenting produce, juice/beer residue, recycling, slow drains
Drain fly	Small, fuzzy, moth-like; sits on walls near sinks and tubs	The organic film inside drains and overflow pipes
House fly	Larger, gray; buzzes at windows	Garbage, organics/compost, decaying matter

A fourth pattern worth knowing: a sudden indoor swarm of large sluggish flies at a window — often after a smell — points to something dead in a wall or void, which is a different (and very solvable) professional job.

How do you get rid of fruit flies?

Remove the ferment. Fruit fly larvae need the yeast produced by fermentation — ripening fruit, vegetable matter, sugary residue. Cornell’s integrated pest management guidance notes the life cycle can complete in about ten days at warm temperatures and a single female can lay as many as 500 eggs — which is why “a few flies near the bananas” becomes a cloud in two weeks.

The hunt list:

Produce — refrigerate or eat what’s ripe; check for the rogue onion or potato at the back of the cabinet.
Recycling and returns — rinse bottles and cans; a beer bottle with a finger of residue is a nursery.
Drains and drips — wet, crusted residue under the dish rack, a sour mop or sponge, the garbage disposal splash guard.
Bins — wash the inside of kitchen and organics bins; residue at the bottom breeds flies even with the bag removed.

Then trap the survivors: a small dish of vinegar (or a piece of ripe banana) under a paper funnel or cling film with holes catches adults. Cornell recommends checking traps daily and refreshing bait every few days. When traps stop filling, you’ve won.

How do you get rid of drain flies?

Scrub the film out of the drain — chemicals alone won’t do it. Drain fly eggs and larvae live in the gelatinous bacterial film that coats the inside of drains, overflow pipes and rarely-used traps. Clemson Extension’s fact sheet is explicit: for long-term control the breeding site must be found and removed, and if a drain cleaner with very hot water doesn’t clear it, mechanical cleaning with a stiff brush is required. Spraying the adults you see on the bathroom wall does nothing about the next generation already in the pipe.

The routine:

Identify the breeding drain — tape a clear cup or tape over suspect drains overnight; the one with flies in the morning is your source.
Brush the drain walls and the overflow opening with a stiff, flexible brush.
Flush with very hot water (and an enzyme/foaming drain gel if you like — applied so it coats the pipe walls).
Run water weekly in unused drains (guest bathroom, floor drains) so traps don’t dry out and films don’t build.

Adults live around two weeks, so a properly cleaned drain goes quiet within days as the survivors age out.

How do you get rid of house flies?

Cut off garbage and keep them out. House flies breed in decaying organic matter — in an NYC apartment building that means garbage, compactor rooms, chute bottoms, and organics bins. In your unit: take trash out frequently, keep lids closed, rinse the bin, and don’t let pet waste or food scraps sit. At the building level, fly pressure in hallways and the trash room is a management problem — compactor areas and shared compost bins need scheduled emptying and cleaning, the same sanitation logic that applies to restaurant pest control. Window screens in good repair handle the rest.

When should you call a professional?

Call in professional fly control when:

Flies persist after you’ve removed every breeding source you can find — there’s a hidden site, often a wall void, a broken drain line, or under an appliance.
The source is shared building infrastructure — trash rooms, compactors, drains under the basement slab — that you can’t access or clean.
A sudden mass of large flies suggests something dead in a wall or ceiling void.
It’s a recurring summer pattern: fly pressure in NYC peaks June through August (see the pest control calendar), and buildings with chronic issues benefit from preventive sanitation programs.

And since drains, moisture and food residue attract more than flies, an apartment with chronic drain-fly or fruit-fly trouble is also on the shortlist for roaches — worth a read of how to get rid of roaches in an NYC apartment while you’re fixing the underlying conditions.