Knats? How do they find their way in?

[steve.long]

It has been quite a summer here in Texas. Over the past few months, I have seen an abundance of knats inside vehicle. I have no food or beverages left out as van is parked most of the time with A/ C running. I purchased a trap and plugged it in and it filled up within weeks so I figured I got them all. I then changed the sticky trap and it continues to collect knats. I have no idea how they are getting in as the van is very clean. Could they possibly be entering thru the black tank vent? Air conditioner? The black tank is only used when travelling if needed and I keep it clean. Grey tank?
Any advice would be appreciated.
Thanks

 

[John&Andrea]

When parked with sewer hook up, do you keep tank valves open? You can get (what I call sewer flies) in you tanks then in the rv. I keep all valves closed and open when I dump the tanks.

 

[GTS225]

Personally, I think they're small enough to squeeze through the window screens. I'll concede that I have no evidence proving or disproving my thoughts.

Roger

 

[jbh]

They're squeezing through the window and vent screens. I have a bug zapper that eliminates them quite well. Small ones are all around $40 on Amazon.

 

[LMHS]

The only gnats I've had lately has come from bringing home fruit.