Outdoor wasp sprays work well. Spray bushes and under and house or shed edges...they hide their nests because they are a delicacy for some birds like the Blue Jay. Put up a bird feeder? If you spray in early morning or evening, it will kill more of them as they are usually out flying around during the daytime.

Wasp sprayers usually have the ability to spray a stream several feet away.

BTW wasps don't usually bother humans unless bothered by humans. If your son keeps running into bushes etc, then yeah, you probably need to spray.

Moth balls put into the shed (if you can stand them) will also repel the wasps. You can also put them around in plant beddings, to initially run them off (works on cats too) if you can handle the smell.

TC