We're not exactly sure what bugs these are, so we call them walla-walla bugs.  They like water.

They live in our greywater planter and one hypothesis is that they come up through the rock (or the pipes) and then seek out anyplace in the house that has moisture.  Favorite hang outs include our shower, the kids bathtub, and the light fixtures above the sink.

Yellow fly paper is catching a lot of them, but they just keep coming.  And coming.  And coming.

I've covered the bulk of the planter with plastic in an effort to keep them trapped there.  This has not worked.  Another hypothesis is that they are living in the water that condenses under pieces of granite that cover the planter dirt.  The granite is there to keep the cats from peeing in the planter.  Of the two, I greatly prefer the bugs to the smell of cat piss.  But my first choice would be to have neither.

To deal with this we are digging the planter down to grade level and paving over it with brick over screening and sand, effectively sealing it up.  If the bugs still come when that is done, we'll add check valves to the pipes that drain into the planter.