Mowing I happen to look up under eave of house and HOLY CRAP! Yellowjackets entering and leaving a hive entry coming out of our soffit that looked revolving front door like a Sale at Cabelas! Tried to kill them with standard wasp hornet spray and that only PO'ed them off so had to call in the big guns to eradicate. Local company and injected a foam right up into the hive entrance and I know he was glad he was suited up since they were not too happy at all. Sometimes just pay it up since trying to do this without gear can get pretty nasty even at night. Sprayed foam insecticide up under the board entrance and it came out the main hive entrance so I bet it was saturated pretty good.