Out shop building seems to be a haven for dirt daubers. It's a concrete block building with a wood decked roof with metal building tin over that. It's shut up most of the time but far from being sealed up. Earlier in the year I sprayed around the eves with bifenthrin. Several weeks later I went back around some of it and a good bit of the inside wood roof structure with malathion. They just seem to keep coming. This mourning I used the leaf blower and a pump up sprayer to hit the wood roof structure again and some on the outside. Those things really make a mess out of stuff. They build nest in all my tool boxes and anything that isn't completely sealed. They get in electric motors and any parts I have laying in bins. They really like pipe fittings. It's hard to believe how much dirt they can haul.  I am thinking maybe some sort of fumigant that could be shut up in there for the day.