Strange influx of house flies suddenly...

[MBAtarga]

We've got something strange going on in the house. We normally might have one house fly in the house in a 2 or 3 week period. They normally show up in the kitchen area - as we have a door leading to the back deck (with a screen door to open there as well) - and the door leading into the garage is nearby as well. Most times we can tell they got in when someone has opened those doors to go in or out of the house. Sometimes when we grill on the back deck and there's lots of going in and out - 1 might sneak in. That's normal.

These past 3 or 4 days- there has been an in-flux of houseflies! I'm talking I killed 7 yesterday - 4 in a 3 minute time period. My wife killed a few others. I killed 2 in the butler pantry room around the corner from the kitchen. This morning I went in the kitchen and killed 3 more in 2 minutes as I was fixing a bagel and coffee.
No one went in or out of the house all night.

We've looked in the kitchen pantry, the butler pantry which is around the corner from the kitchen, under the kitchen sink, ran a LOT of water in both kitchen drains, etc. We even plugged both drains in the sink and 2 flies showed up within 30 minutes. We've checked the fresh fruit produce, and the bag of Vidalia onions in the pantry. We are out of potatoes - so not coming from there. Everything else is sealed up in a box or plastic storage or the fridge or freezer.

We've got no other ideas. Anybody got suggestions on where to look or how they might have entered the house? I'm thinking there must be a nest/swarm of them but don't know where else to look.

[Starless]

We have the same setup as you, sliders from the kitchen to the deck where the grill is. We also get very few flies. Last summer during a heat wave we had the A/C on. Somehow the house was loaded with flies. Couldn't keep up. Still have no idea how they were getting in or of something went bad and they were breeding. No bad smell and we didn't find anything. I did read that if you have an infestation, it probably came from dozens of eggs hatching in your attic, garage etc. from some spoiled food or dead animal that somehow got into your dwelling.The one thing we did to get rid of them without making a stain on walls or windows is we used the shop vac to suck them in and let them die.

[dennis in se pa]

Experiencing that in SE PA also.

[KFC911]

Flying critters are Covid surging this year .... seeing more butterflies, etc. than I can recall in years. Lightning Bugs (fireflies) keeping my backyard illuminated like never before. I'd bet one fly or a few gained entry... then eggs.

[Tidybuoy]

I don't get a lot of flys throughout the year until hot summer (which is now). I keep raid fly spray handy and I spray the outside garbage cans daily and that keeps the population down.

My parents, who live a few miles away, keep food scraps in a bag in the freezer until garbage night. I don't have enough room for that (or the patience) but that is something that keeps the population down.

You could also have neighbors whose garbage is attracting flys. And, outside pet food will also attract flys.

Lastly, look for any garbage that may be inside of a plastic bag that flys have gotten into. Once they're in their, you could have thousands of maggots in a very short period (like hours). Even if you kill them all, some will survive and produce flys in a day or so.

[Noah930]

The past couple years, I've had this happen, too. Often it's for about 1-2 weeks in the middle of summer. All windows and doors are kept closed because of the heat and AC, so there shouldn't be easy access into the house for them. Certainly not continuous access. Only we'll get an invasion of 30-50 per day. I've checked behind appliances/cabinets, in the attic, etc. No obvious signs of a dead rodent/animal. I pour bleach down sinks/showers/tubs. So I don't know from where they come. But then, just as mysteriously as they come, they disappear.

[jyl]

We get that sometimes, like once a year or so. No matter how much we clean, the flies are still there. I think you just have to eradicate and move on. A fly laid eggs in something tiny and hidden that you'll never find. Fly strips work over a couple of days, a vacuum cleaner with long nozzle is kind of fun, a laser would be funner but doesn't work (I've tried), and a set-and-leave spray bomb works in a couple hours. I've used the bombs sold for fleas and ticks, they seem to work for flies too. Use one bomb per infested room, they don't hurt plants and you'll air the house out for an hour or so before re-occupying.

[Zeke]

Sounds to me like one laid eggs in your house. Check around your window panes.

[BK911]

Something dead and rotting somewhere in your house.
Could be a mouse in some wall.

[porsche4life]

Hang one of these outside. They stink like hell after a week but they catch every fly in the area.

Disposable Fly Trap Indoor Insect Repeller https://www.lowes.com/pd/BLACK-FLAG-1-Count-Insect-Repeller/3818465

The old school fly paper rolls work well inside too. We get the same thing occasionally with a random swarm of flys. No clue where the little bastards come from, amazing they survive at all here in the summer.

[gregpark]

You need one of these, they're awesome

[pwd72s]

Flies? I have a horsey set neighbor...so hang a fly trap in the woodshed. Try to catch 'em before they get to the house. Tips: It can stink pretty badly, so hang some distance from the house. Also, the dead flies can become the bait in their own right, so when the trap gets full, I leave an inch or so of dead flies, add water, rehang. This isn't exactly like mine, but close in design...should work.

(edit) If you live in tract housing with a tiny yard, ignore this. They ARE stinky. I'd suggest a minimum of 100 feet from the house. Set so when the flies emerge from the horse krap, prevailing breezes lead then to the trap before they reach the house.

I tried disposables...they got $pendy for me with the number of flies generated by the neighbor's horses...was going through a disposable every couple of days. Thus the refillable route.

https://www.amazon.com/Victor-M380-Reusable-Outdoor-Traps/dp/B089B6GSGJ/ref=bmx_8212rv8o_5/135-7389151-7258058?pd_rd_w=pbkap&pf_rd_p=1f75fbb3-7d95-464f-8182-952155c0316b&pf_rd_r=Z53742S7XYHKJZF6Z0A0&pd_rd_r=69ee25b1-afa3-4b73-8441-350a4045091b&pd_rd_wg=5MmkW&pd_rd_i=B089B6GSGJ&psc=1

[pwd72s]

More than you really need to know...but the females lay their eggs in organic rotting material...that can be animal krap, dead kritters, pretty much anything that is rotting.
This feeds the larvae...

https://en.wikipedia.org/wiki/Housefly

[pmax]

Anything died ?

[john70t]

Originally Posted by BK911

Something dead and rotting somewhere in your house.
Could be a mouse in some wall.

This. They don't reproduce without a food source.

Turn off the lights, open the window, and shoo them outside with a towel.

[Tobra]

Anyone summon a demon in the neighborhood lately?

[pwd72s]

I wouldn't say it's aliens...but some might.

[MBAtarga]

My wife and her mother-in-law have the smelling capabilities of bloodhounds. They can't find anything rotten.

And an update - I've killed 2 more flies since breakfast and the wife 2 as well.

[pmax]

Checked the attic or crawl space for half eaten rats ?

[Noah930]

Originally Posted by gregpark

You need one of these, they're awesome

Ha ha. A friend has one of those. The dad and kids love it.