phorid flys help

you have a dead animal (mouse or otherwise) somewhere in the trailer that is providing food and "hatching" for the flies.

All I can think of is lye down all of the drains and then closing them off. Your lines should only be open when actively draining the tanks.

try boiling water followed by vinegar and baking soda in the traps.

Do you have any plants and flowers pots inside the trailer? They can lay eggs in the top layer of the damp dirt. By adding a half inch of sand on top. The top layer of sand will dry out after watering. Any eggs layed in the sand will die and not hatch out. They need a damp environment to gestate and hatch.

You might also place a couple small containers out with some apple cider vinegar and a few drops of soap. I use a couple of short and fat pill bottles that hold about 2 to 3 ounces with about an ounce of vinegar in each of them.

I have the vinegar thing out and 3 fly strips. I caught alot.. It seems i get rid of most of them one day and I go in the bathroom the next and they are there..

I scrubbed the bathroom down with bleach rag.
I turned off water to camper and opened toilet valve and looked down there.. NO FLYS..
I poured bleach down all drains closed stoppers over night.. still flys.

I keep a pillow and cover on the bath fan. I went on roof and lifted max air vent cover. Pine needles and seemed flys were around there . I took off clips and flipped cover open. I will leave it like that and hope the sun will dry that area under vent cover. ( But how would they get in? I never open vent.)

I even took inside shroud all apart to see between roof.. Nothing.

I closed the vent fan dor for the stove. ( I dont think they are coming in there.)

I took the electric cord insert off side of camper to see whats in there. The cord winds up under tub. No flys in there. I replaced and stuffed paper towels in there and closed door and slide where cord goes in camper.

I checked all underpass storage.. Nothing..

I carawled under camper and all propane hose tubes are foamed properly.

Under body paper all intact. no rips or tears..

I checked all cabinets for food, all drawers, under dinette, mattresses, ect ect etc..

next to putting screen over fridge vent I have no clue..

If in grey tank how would they get up traps, and survive my bleaching? I even let the grey fill up all the way before dump..

So WTF..

I just replaced all fly strips. a few days they were filled up..

No plants or fruit in camper.

Maybe ill get pics tomorrow ..

Its just maddening!!!!!!!!!!!!

did you do the boiling water?

Check under the sinks where your plumbing lines enter. I have stuffed stainless steel scouring pads in the gaps and then spray foamed them in place to stop mice from entering.

they seem to of dissipated a huge amount. I went on roof and flipped the vent max air cover over. seems they were a lot in the dampness and pine needles up there. I left cove hinged over so the sc sun dried it out. I still cant see that they were getting in that vent and the main vent is closed.

And I had a pillow and fan cover on it the whole time.

But I did a lot of things simultaneously.

Bleach in drains
closed grey valve
Let tank fill up to top and bleach tanks
Keep stoppers closed
Closed stove vent( Locked it closed)
Pulled studor vents under both sinks and rattled them to make sure they work. reinstalled. ( Incase they were in grey tank.)