Fruit Flies or ?

[richardbrucewinquestjr]

When we pulled our fith wheel out this year we found the shower stall had these little fruit flies all over the floor. The only thing down that drain last fall was RV anti freeze, anyone out there ever had this problem and are these fruit flies or small flies of another nature.

[TitanMike]

As I travel around the country it seems like I pick up "hitchhikers" of varying types and sizes.

Seems like they all end up on the shower floor after the winter. I just flush them down the drain and don't give them another thought.
Could be that they are attracted to the smell of the RV antifreeze.

Just make sure the garbage pail has been emptied before closing up for the winter and any food sources are removed.

Maybe even spray a little "RAID" around before you close up and then clean counters and table in the spring.

[richardbrucewinquestjr]

Thanks I was curious as to where they would have come from. We traveled on a 6500 mile trip out west last year and maybe could have hitchhiked from one of our stops.

[A32Deuce]

They may/could be sewer flys. Some of the CGs we have visited in the past had them.

[TitanMike]

Originally Posted by A32Deuce

They may/could be sewer flys. Some of the CGs we have visited in the past had them.

How are they making their way into the RV? If the black tank valve is closed while hooked up, you have water in P-traps of sinks and shower, can't enter that way.

In 40 years I have yet to encounter "Sewer Flies" but I've seen more than my share of Fruit Flies, Horse Flies, Gnats, and countless other flies that live around the country. Sometimes even hordes of "Lady Bugs".

My late wife loved bananas. For some reason it appears that every bunch or bananas comes with it's own colony of fruit flies and I finally had to make sure the peels were disposed of in campground trash containers before bedtime.

[AceCombat]

Originally Posted by TitanMike

How are they making their way into the RV? If the black tank valve is closed while hooked up, you have water in P-traps of sinks and shower, can't enter that way.

In 40 years I have yet to encounter "Sewer Flies" but I've seen more than my share of Fruit Flies, Horse Flies, Gnats, and countless other flies that live around the country. Sometimes even hordes of "Lady Bugs".

My late wife loved bananas. For some reason it appears that every bunch or bananas comes with it's own colony of fruit flies and I finally had to make sure the peels were disposed of in campground trash containers before bedtime.

The sewer flies can get in through the bathroom vent fan or they go down your vent stack from the roof and can make their way up the pipes. They look like a house flie only miniature. Maybe 4mm to 5mm fruit flies are much smaller and have huge red eyes compared to their body. If theres a way in they will find it

[TitanMike]

Originally Posted by AceCombat

The sewer flies can get in through the bathroom vent fan or they go down your vent stack from the roof and can make their way up the pipes. They look like a house flie only miniature. Maybe 4mm to 5mm fruit flies are much smaller and have huge red eyes compared to their body. If theres a way in they will find it

Every TT I've ever owned has had screens on the bathroom vent. As for entering the vent stack, the only way they could possibly enter would be to fly out the toilet valve when I open it.

Apparently I'm missing out as in over 40 years I have yet to see one.

FWIW, Wikipedia shows "Drain Flies, or Sewer Gnats as looking more like a moth.

[A32Deuce]

If you leave your gray tank open they can get in to the tank. Going down the road can/will remove enough water from the p trap so they can enter your unit. That's why you see them in the shower. Now just because someonenever saw one does not mean they don't exist! May be a more Tec name, but if you open the sewer trap cover to hook up and these little things with bigger wings then body's fly out, then to me they are swear flys!
My class C does not have a screen in the roof vent.

[Walholler]

I have never seen a roof vent that did not have a screen, if you have a vent that does not have a screen, then yours is missing. I own a Prime Time Crusader Lite that is sealed so tight around all of the openings that the only way anything is going to enter is through the door. Just after purchasing the 5th wheel new, I installed screens over all of the openings on the outside, even the exhaust on water heater and furnace. No mud building wasp allowed.

[Freetyme]

Not sure where they come from, but the shower skylight is where they'll congregate trying to get out, eventually die and fall to the shower floor.

[Tundra 2014]

Different bug, but we started sprinkling Sevin dust around the down riggers to keep the ants out, The "Sugar Ants" are bad in the south and can and will get in any small gap. We have used sulfur for the same purpose, plus it keeps the snakes away.

[ben31]

Drain Flies are quite different from house flies. See https://en.wikipedia.org/wiki/Drain_fly

Yes, drain flies can come up the sewer hose, if the grey valve is left open. You can, however, make your own p-trap with the sewer hose to keep them out. Just leave a dip in the hose enough to allow some water to stand in it.

Personally, I prefer to leave the valves closed and only empty them, when needed. This prevents anything from sneaking into the grey tank.

Lastly, I agree with Tundra 2014. Sevin dust around ANYTHING that touches the ground is a great way to keep crawly bugs from getting into your rig.

[fella10]

The OP said the flies where there AFTER the winter storage, ... a "p" trap can dry out, even antifreeze, and with several months in storage it's possible that's what happened, ... with the "p" trap open, there's usually enough "stuff" in the gray tank to attract the little flies, where they would lay eggs and the larva would make more flies, ... ...

[TitanMike]

Originally Posted by ben31

Drain Flies are quite different from house flies. See https://en.wikipedia.org/wiki/Drain_fly

Yes, drain flies can come up the sewer hose, if the grey valve is left open. You can, however, make your own p-trap with the sewer hose to keep them out. Just leave a dip in the hose enough to allow some water to stand in it.

Personally, I prefer to leave the valves closed and only empty them, when needed. This prevents anything from sneaking into the grey tank.

Lastly, I agree with Tundra 2014. Sevin dust around ANYTHING that touches the ground is a great way to keep crawly bugs from getting into your rig.

Can't disagree that Sevin will kill bugs but I'd only put it down on my own property. Doing so at a campsite can leave the stuff exposed when you leave and the next occupant may have little kids playing on or near the area you put it down. May seem harmless to adults but kids have a far greater tendency to put their hands in the dirt and eventually in their mouths. Adults tend to wash hands more often too.