Smaller wall vents or fan inserts?

[pdude]

In California where I'm trying to keep dust and little insects from venturing into the garage through my garage vents. Was considering getting a screen with a smaller mesh size and overlay it over the existing mesh as most of the mesh I've seen online more or less appear to be the same size.

Any other ideas people have tried?

 

[nadogail]

I have learned to embrace all living things. Some not so closely.

 

[Dumber than lumber]

Could you mix up boric acid with water and then use a spray bottle to coat the existing screen?
I know that boric acid powder is a known and cheap solution for roaches and ants.
Alternatively maybe some industrial strength bug spray.

 

[The Cobbler]

what about window screen?

 

[pdude]

Been thinking window screen as the only other option. May opt for that one.