What's with all the flies?

[milliemchi]

Every spring, we get an odd fly buzzing around the house, which is twice as big as the 'normal' ones, so I figure it's from last year and coming out of hibernation. We generally wait for it to come to our glass back door, let it out, and that's the end of it. We have screens on our windows, so the rest of the year we maybe see five flies total. Or maybe a dozen. But not more than that. Last night I saw one of those, thought 'oh, again', let it out, and thought that was it. By tonight, I have killed 20 more, big ones and gigantic ones, and a few normal sized ones.  This is really, really unusual. Anybody have a thought about what is going on? I never had 21 in the house at any one time. It's only 2-3, and 5 once after spending 6 hours outside of the house. It feels like they are slowly coming out of somewhere one by one. We do leave the porch door open from time to time, but I don't see 21 flies coming inside in a single 15 minute open door session, and I definitely did not have 21 last night. The weather did not change much since two days ago. I wasn't cooking either. Any ideas? I find flies gross, and it's beginning to freak me out. Every weird noise sounds like a fly buzzing or hitting a wall. Every light feeling on my skin feels like a fly walking on me.

[milliemchi]

24 as of this morning, and I still have 2 flying around and 5 between various (closed) windows and their (closed) respective screens. I have no idea how they get in there.

Do they hatch big, or do they hatch small and then grow? I see them in various sizes, mostly bigger, so I assume they're on the older side. But maybe there is actually some gross maggot source. Nothing stinks though.

[Hargrove]

Large plant seeds left somewhere, even.

[milliemchi]

33 and counting... I was able to get 4 out of the house by waiting for them to land on the glass back door and shooing them out... much less work than chasing after them...  this is beginning to feel like the new normal...

[daverobev]

Where are you?

[albireo13]

Blow-flys!
Harbinger of the zombie apacolypse !

[ChpBstrd]

2 cheap solutions:

1) Obtain 7' of 36" wide screen material. Glue it to a 36" yardstick. Tack yardstick above door. This simple curtain will deflect 90% of bugs.

2) Build fly traps out of a bottle, a paper towel pipe, and a festering piece of meat/cheese.

Overall, look for that one window that didn't close all the way. Double-hung windows are notorious for having the top part slide down over time if the lock doesn't catch.

Also, check the bottom of all trash cans, the dog food bucket, under sinks, the recycle/compost bin, etc. Bathroom trash cans are often forgotten about long enough for maggots to grow on feminine hygiene products, snot rags, etc.

[milliemchi]

N=49
Every time I kill one, I have to wash my hands, it's hard on my skin.

Daverobev: Chicago, South Side... urban, but with lots of trees and parks

Wikipedia:  "Having emerged from the pupae, the flies cease to grow; small flies are not necessarily young flies, but are instead the result of getting insufficient food during the larval stage."

[milliemchi]

2 cheap solutions:

1) Obtain 7' of 36" wide screen material. Glue it to a 36" yardstick. Tack yardstick above door. This simple curtain will deflect 90% of bugs.

2) Build fly traps out of a bottle, a paper towel pipe, and a festering piece of meat/cheese.

Overall, look for that one window that didn't close all the way. Double-hung windows are notorious for having the top part slide down over time if the lock doesn't catch.

Also, check the bottom of all trash cans, the dog food bucket, under sinks, the recycle/compost bin, etc. Bathroom trash cans are often forgotten about long enough for maggots to grow on feminine hygiene products, snot rags, etc.

1) I am positive they are not coming in through doors or windows. My husband says they might be coming in through the chimney, though we've never seen that before.

2) I will task my husband with making the trap tomorrow. Instead of meat, would honey work, or something else that's less unsanitary than raw meat?

I'll check the trash cans. We were away for a week two weeks ago, so that would fit, but I think we threw all the trash before we left, including the bathroom cans. It would also fit if we forgot some food somewhere that rotted enough that the stink was gone by the time we came back. But that would have to be a big pile of crap to have 49 big-ass flies emerge from it. Maybe. I'll check.

[Linea_Norway]

There can be food or dead animals in your walls. We found oak nuts on the top of ceiling plates in the living room, put there by mice, most likely. We had mice eating poison and dying within a wall inside the house. Birds can drop into the chimney and not be able to fly out and die in there. Solution: fire up in the chimney.

I feel for you. We have had this issue with an occasional big wasp crawling sleepy over the wall in the winter. They came out of a hole in the wall, some electricity outlet place that was not in use. We covered the hole and the problem disappeared.