Tiny black flies all over house. Help!

[Jazz129]

New here and no idea where this thread fits. Trying MN in thr hope of some expertise as I’m at the end of my tether now with small black flies which appear in ‘waves’ ie they’ll come for a few weeks, be everywhere, then I’ll get them down/ gone and perhaps up to 6 months later they’ll reappear. We first noticed it in covid when we had a particularly bad episode in the height of summer after lots of wet, humid weather. I had thought they were related to a newly laid patio but that turned out not to be the case.
From the hours of research I’ve done I think they are phorid flies? I see them in other houses, on windowsills etc but never to the extent I see them in hours. I’ve had the drains in the in the kitchen and waste pipe checked. I have no potted plants (quite literally threw them out) and clean/ bleach drains etc. no pets (fish recently but prior to that we had none).
They appear to like the front room the best, which is north facing and cooler. Outside we have shingle laid up to the house walls, rather than a concrete or slabbed path. In fact there is a lot of shingle, and I wonder if this and the mulch which potentially accumulates isa source, and then they just get in, and that’s it?!
Any ideas? Anyone?! And thank you in advance!!!

Google cluster flies.

We had them in an Army quarter.

You need to treat twice a year if so.

It's about the right time for them to wake up too.

Thanks! I’m not sure they are cluster flies due to size - these are tiny and I think walk across windows rather than fly (although they do fly within the room). Smallest ones only around 2 mm say, but the larger ones can be about 5-6mm. Here is a much better image.
We’ve also noticed they appear throughout the seasons, but I do think there is a link with the amount of rain.

You didn't say which country you're in OP.

In UK fruit/compost/vinegar flies often get in to houses on bananas, interestingly enough. Drains and potted plants are usual breeding spots, but you've taken care of those, haven't you?

Have you tried sticky traps? A bit unsightly, but they do work

Vinegar traps are cheap and effective too.

Clingfilm over a pot with little bit of washing-up liquid in vinegar. Pierce with a small hole and place in a warm spot

ooops, sorry. I’m in the UK. So the weather is quite mild at the moment and a bit wet. I see these flies in other environments - eg other peoples houses, but never to the extent they come to ours. I’ve meticulously cleaned every plug hole / drip tray/ floor in the house. There are no leaks in any pipe work etc - we’ve had this checked. I’ve used sticky traps but with these flies they aren’t particularly effective. Definitely not fruit flies (we’ve had those!). Just so frustrating!!

They could be fungus gnats?

We get them, it's because our neighbours throw bags of rubbish out in their garden and they get opened by foxes and then the fruit and other stuff rots round the back gardens.

Literally not much you can do as you say you've cleaned, had drains checked. I tend to put a small piece of strawberry in a pint glass, with a cone of paper, they smell the fruit, fly in but then can't get out again. That sorts them from flying round.

We asked the environmental health team to look into our home in case and they confirmed it's down to the skanks next door but they've been told and told to sort it and don't bother, their landlord won't act either as they pay rent so he doesn't care.

All you can do is not have any fruits or veg out on the sides and remove as soon as it turns.

Have you got house plants? If so they are probably fungus gnats living in the soil.

Thanks all. It’s baffling and every time it happens has a huge effect on my mental health (which sounds ridiculous, I know, but it feels like nobody else understands).

I’m hoping to find and entomologist on here I think haha. I hope they are fungus gnats (bizarrely!) but I’m not sure, and thing possibly phorid flies because they tend to run/ scuttle on surfaces including window panes.

They are mostly found downstairs. I do wonder if they come in from outdoors, breed somewhere in cracks and crevices (I’ve gone around the house with sealant guns many a time!) and then bang, it’s an outbreak. Our living room windows at the front of the house get a fair few, and we do get some mould build up in the corners (not on the walls, but around the window pane edge). I go around and wipe with bleach/ mould killer from time to time, but wonder if that’s what they like. Not a single potted plant in sight. I got rid long ago!
I also wonder if it’s the general environment around our house. We have a shingle path that is in front of our living room and extends round most of thr perimeter of the house. There are also drains/ down pipes so the wet runs off into it. I have been outside and dug around and can’t see any evidence of the flies, but they do live outside as I can often see them on the other side of the glass when sat indoors. I wonder if it’s just perfect conditions there and then it’s just a case of them coming in during particularly wet spells?!
Unfortunately the fly traps / fruit fly traps don’t work. I’ve been tempted by one of those electric fly zappers they have in butchers shops and think that might be my next move! So far the only thing that does work is splatting them - quite easy to do because they aren’t that fast - and spraying with standard fly killer from wilko.

Sorry to hear this! It must be hard with neighbours like that. We are fortunate we have lovely neighbours who are very tidy and look after their rubbish, wash their bins erc. there’s definitely nothing like that I can blame it on, which is why it’s so puzzling!

Sounds the same as the ones I have. Having read about a few types of flies here I think mine are fruit flies. Had a problem with them since my elderly neighbour died and was not discovered for a very long time. I appollogize for that aweful image. Tiny little things almost like a speck of dust until you see it move. Tend to only see 1 - 3 of them at any given time, But have twice now found the lavae breeding in my rubbish bin. The revolting smell of these lavae or probably the paupa stage is what makes me think they originated from the neighbour. As I smelled this when I put a letter through her door that had been incorrectly delived to me. It was due to that smell that I alerted the landlord that I thought something might be up. Anyway. Still get the flies, over a year later. I suspect they are nesting in ventilation pipes. Dormant over the winter months and now have that aweful smell in my bathroom ventilation pipe again.

Yes I too find that they can have an effect on your mental health.

Hoover them up. As soon as you see even one get the hoover out because they multiply rapidly.

Hi did you manage to identify these flies and eradicate the problem?
all best

We had these - cleaned out our drains but they came back. The thing I found that really got rid of them was I read somewhere that if you filled a container with red wine almost up to the top, covered with cling film and made small holes in it, the flies would be attracted to it, be unable to get out and drown in the wine. So I got some crappy British red from the corner shop, filled a large beaker and honestly it worked when nothing else had. I was skeptical but it really worked!

I had flies in my house that look like the ones in your photos. They were black humpback phorid flies.
They were appearing in my house for about a year after the covid lockdown commenced. Apparently, when everyone had to stay at home, there were obviously larger amounts of household waste around homes which increased fly numbers.
Phorid flies spread germs and are difficult to get rid of, unless you can find the source breeding area.
I tried everything and blasted my house with insecticide foggers and sprays, constantly bleaching the drains and cleaning but I couldn't work out where they were coming from.
Eventually I went up into my loft and saw that the cold water header tank (supposedly for extra water pressure with upstairs shower) had lots of insect particles in the water, despite having a lid.
I had the old tank removed and a new cold tank fitted.
However, still flies, so by that time I was really freaked out and concerned that the flies were breeding in the tank overflow pipe, as it was old and may not have had an internal filter.

Very soon after replacing the tank, I ended up having it removed completely and buying a new combi boiler which doesn't need any water tanks or cylinder. After the water tank was removed from the loft, the flies slowly disappeared.
Humpback phorid flies can vary in colour.
The ones in my house were jet black.
They are attracted to decaying organic matter. This can be fruit/veg or meat/flesh.
They are also known as "coffin flies" for obvious reasons and "scuttle" flies because they run (scuttle) across surfaces.
They breed in damp places, in drains or soil, gravel, under concrete, in bins, anywhere with damp decaying matter.
They can also appear in homes if there is a dead animal in wall cavities, such as a mouse. They can also enter through any hairline crack, such as where the toilet is joined to the waste pipe.
Bleach doesn't kill the larvae in drains. Bio type drain cleaner for grease removal is required to destroy that stage of development and needs to be repeatedly applied daily for a few weeks to keep them away.

As you've mentioned gravel outside your home, this made me think that these flies could be the type you’re having problems with.
This article also mentions gravel. diypestcontrol.com/phorid-flies.htm
There are other fly types mentioned in this article which may be helpful if you don't think your problem is phorid flies.
I really hope that you've got rid of them by now.

It certainly can affect mental health. I have an insect phobia now. If I open the windows in my home, I always have discreet fly mesh over the opening. It's the type that's secured by a thin strip of white velcro, so on white window frames you don't notice it when the fly mesh isn't in use.
I came across your post whilst browsing so thought I'd reply in case it helps.

Thank you so much! These replies are really helpful. Happy to say after much bewilderment and constant cleaning I think we cracked the source. There are flies outside, and I notice they increase when it’s damp. But a particular plant in the garden was full of them. No idea what it was bht as I lifted it, they were all within it and the roots system! It was very close to a window so I believe they were breeding there and then entering in some way, even if we couldn’t see it. I fully removed the plant and we’ve seen far less. The odd one or two but as I see out and about and I have seen in other homes. It’s quite frustrating at the time though as some of the most obvious places yielded no results!

hello, I’m really curious to find out if you got these flies sorted? I’m having the same problem I moved into my new home in October just past, I moved into a fruit fly infestation. I tried everything I had pest control out, environment health, plumbers absolutely everything they wouldn’t budge. Eventually with the cold weather I presume they started dying off and we didn’t see as many as we would but now we are experiencing these awful small black flies 💔 just as we got rid of fruit flies I left sticky traps and vinegar and dish soap traps completely cleared out my drains and now we have these black ones I am at my absolute wits end I don’t know what to do anymore and it’s seriously affecting my mental health I’m 21 and have a severely autistic non verbal 4 year old who tries to eat them, I’ve done everything I can think of I really would love help if anyone has any advice thank you so much, Louise x

Hello
I've had the same problem after moving into a new house this year. Reported it to builders and drains were checked.
Turned out the builder hadn’t put a sewage pipe in the property.
It’s been a nightmare!
They sent a well known pest control company in but it’s not killed the source .
I thought they’d gone with the low temperatures but I put my heating on over the weekend and they’re back!
It might be worth contacting the developer.