1.   I suggest building a vent in each board that plugs the opening between rafters.

2.   It may be difficult to plug all openings to the attic, but the problem of wasps in the attic is not as severe as that in the ceiling.

3.   Plug those openings with a wet rag.

4.   To prevent it from happening again, plug all openings to the space between ceiling and floor.

5.   Asphyxia also was suspected because the family had plugged all openings to their home with rags to block out the sun.