Choosing the screening for an attic vent

https://www.onyxxteriors.com/info/screen.php

The bug screen of fiberglass is common but never good if there are too many wasps and grasshoppers to chew through it.  Aluminum bug screen lasts much longer even with the heat and cold elements.

Wire mesh can be added to the aluminum screen for larger critters such as raccoons and squirrels and birds.  

Or the non vented is just a black metal backing to prevent air and water intrusion completely.  Your choice.  Fully customizable.