Super Blue 72 is right about the siding it happens a lot. And very hard to get rid of. You can hear them buzzing behind the wall. I had them when I use to have a house...not an old house but lovely new siding...I kept finding wasps in the house and was getting real spooked about it...then one night when it was quiet and only me...I could hear this buzzing quite loud...coming from the wall
I had to call the professionals on that problem...
As for what do they like...anything sweet...if you notice if you eat outside as I do a lot suddenly the area will be swarming if there is something sweet and am not even talking candy sweet. Example...I bring out sweet & sour ribs and they are all over the place
So you could leave out juice...pops...sweet and sour sauce
When camping cooking up bacon brings them on and even beer...they would be all over swarming the bottles
Good luck !!